Virulence: The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.Physical Fitness: The ability to carry out daily tasks and perform physical activities in a highly functional state, often as a result of physical conditioning.Genetic Fitness: The capability of an organism to survive and reproduce. The phenotypic expression of the genotype in a particular environment determines how genetically fit an organism will be.Bacterial Proteins: Proteins found in any species of bacterium.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Genes, Bacterial: The functional hereditary units of BACTERIA.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Plant Diseases: Diseases of plants.Host-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Bacterial Adhesion: Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Quorum Sensing: A phenomenon where microorganisms communicate and coordinate their behavior by the accumulation of signaling molecules. A reaction occurs when a substance accumulates to a sufficient concentration. This is most commonly seen in bacteria.Escherichia coli Infections: Infections with bacteria of the species ESCHERICHIA COLI.Genomic Islands: Distinct units in some bacterial, bacteriophage or plasmid GENOMES that are types of MOBILE GENETIC ELEMENTS. Encoded in them are a variety of fitness conferring genes, such as VIRULENCE FACTORS (in "pathogenicity islands or islets"), ANTIBIOTIC RESISTANCE genes, or genes required for SYMBIOSIS (in "symbiosis islands or islets"). They range in size from 10 - 500 kilobases, and their GC CONTENT and CODON usage differ from the rest of the genome. They typically contain an INTEGRASE gene, although in some cases this gene has been deleted resulting in "anchored genomic islands".Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Hemolysin Proteins: Proteins from BACTERIA and FUNGI that are soluble enough to be secreted to target ERYTHROCYTES and insert into the membrane to form beta-barrel pores. Biosynthesis may be regulated by HEMOLYSIN FACTORS.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.Genetic Variation: Genotypic differences observed among individuals in a population.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Models, Genetic: Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Bacterial Toxins: Toxic substances formed in or elaborated by bacteria; they are usually proteins with high molecular weight and antigenicity; some are used as antibiotics and some to skin test for the presence of or susceptibility to certain diseases.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Mutagenesis, Insertional: Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.Adaptation, Biological: Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Adhesins, Bacterial: Cell-surface components or appendages of bacteria that facilitate adhesion (BACTERIAL ADHESION) to other cells or to inanimate surfaces. Most fimbriae (FIMBRIAE, BACTERIAL) of gram-negative bacteria function as adhesins, but in many cases it is a minor subunit protein at the tip of the fimbriae that is the actual adhesin. In gram-positive bacteria, a protein or polysaccharide surface layer serves as the specific adhesin. What is sometimes called polymeric adhesin (BIOFILMS) is distinct from protein adhesin.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Mice, Inbred BALB CGenetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.Salmonella typhimurium: A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.Yersinia pestis: The etiologic agent of PLAGUE in man, rats, ground squirrels, and other rodents.Bacterial Outer Membrane Proteins: Proteins isolated from the outer membrane of Gram-negative bacteria.Lethal Dose 50: The dose amount of poisonous or toxic substance or dose of ionizing radiation required to kill 50% of the tested population.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Serial Passage: Inoculation of a series of animals or in vitro tissue with an infectious bacterium or virus, as in VIRULENCE studies and the development of vaccines.Pseudomonas aeruginosa: A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. aeruginosa is a major agent of nosocomial infection.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Microbial Viability: Ability of a microbe to survive under given conditions. This can also be related to a colony's ability to replicate.Exercise: Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.Streptococcus pyogenes: A species of gram-positive, coccoid bacteria isolated from skin lesions, blood, inflammatory exudates, and the upper respiratory tract of humans. It is a group A hemolytic Streptococcus that can cause SCARLET FEVER and RHEUMATIC FEVER.Host-Parasite Interactions: The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Vibrio cholerae: The etiologic agent of CHOLERA.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Cryptococcus neoformans: A species of the fungus CRYPTOCOCCUS. Its teleomorph is Filobasidiella neoformans.Candida albicans: A unicellular budding fungus which is the principal pathogenic species causing CANDIDIASIS (moniliasis).Staphylococcus aureus: Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications.Cardiovascular Physiological Phenomena: Processes and properties of the CARDIOVASCULAR SYSTEM as a whole or of any of its parts.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.DNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.Fungal Proteins: Proteins found in any species of fungus.Listeria monocytogenes: A species of gram-positive, rod-shaped bacteria widely distributed in nature. It has been isolated from sewage, soil, silage, and from feces of healthy animals and man. Infection with this bacterium leads to encephalitis, meningitis, endocarditis, and abortion.Shigella flexneri: A bacterium which is one of the etiologic agents of bacillary dysentery (DYSENTERY, BACILLARY) and sometimes of infantile gastroenteritis.Serotyping: Process of determining and distinguishing species of bacteria or viruses based on antigens they share.Regulon: In eukaryotes, a genetic unit consisting of a noncontiguous group of genes under the control of a single regulator gene. In bacteria, regulons are global regulatory systems involved in the interplay of pleiotropic regulatory domains and consist of several OPERONS.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Yersinia pseudotuberculosis: A human and animal pathogen causing mesenteric lymphadenitis, diarrhea, and bacteremia.Colony Count, Microbial: Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.Yersinia enterocolitica: A species of the genus YERSINIA, isolated from both man and animal. It is a frequent cause of bacterial gastroenteritis in children.Streptococcal Infections: Infections with bacteria of the genus STREPTOCOCCUS.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.Epistasis, Genetic: A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.Gene Knockout Techniques: Techniques to alter a gene sequence that result in an inactivated gene, or one in which the expression can be inactivated at a chosen time during development to study the loss of function of a gene.Operon: In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.Drug Resistance, Bacterial: The ability of bacteria to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).Fimbriae, Bacterial: Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly Enterobacteriaceae and Neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and hemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX).Exercise Test: Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.Salmonella Infections, Animal: Infections in animals with bacteria of the genus SALMONELLA.Plague: An acute infectious disease caused by YERSINIA PESTIS that affects humans, wild rodents, and their ectoparasites. This condition persists due to its firm entrenchment in sylvatic rodent-flea ecosystems throughout the world. Bubonic plague is the most common form.Sexual Behavior, Animal: Sexual activities of animals.Bacterial Capsules: An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Hyphae: Microscopic threadlike filaments in FUNGI that are filled with a layer of protoplasm. Collectively, the hyphae make up the MYCELIUM.Oxygen Consumption: The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Inbreeding: The mating of plants or non-human animals which are closely related genetically.Macrophages: The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)Fimbriae Proteins: Proteins that are structural components of bacterial fimbriae (FIMBRIAE, BACTERIAL) or sex pili (PILI, SEX).Yersinia pseudotuberculosis Infections: Infections with bacteria of the species YERSINIA PSEUDOTUBERCULOSIS.Respiratory Physiological Phenomena: Physiological processes and properties of the RESPIRATORY SYSTEM as a whole or of any of its parts.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Siderophores: Low-molecular-weight compounds produced by microorganisms that aid in the transport and sequestration of ferric iron. (The Encyclopedia of Molecular Biology, 1994)Salmonella: A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that utilizes citrate as a sole carbon source. It is pathogenic for humans, causing enteric fevers, gastroenteritis, and bacteremia. Food poisoning is the most common clinical manifestation. Organisms within this genus are separated on the basis of antigenic characteristics, sugar fermentation patterns, and bacteriophage susceptibility.Gene Expression Regulation, Fungal: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in fungi.Mutagenesis: Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.Vibrio Infections: Infections with bacteria of the genus VIBRIO.Genetics, Population: The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.Bacterial Secretion Systems: In GRAM NEGATIVE BACTERIA, multiprotein complexes that function to translocate pathogen protein effector molecules across the bacterial cell envelope, often directly into the host. These effectors are involved in producing surface structures for adhesion, bacterial motility, manipulation of host functions, modulation of host defense responses, and other functions involved in facilitating survival of the pathogen. Several of the systems have homologous components functioning similarly in GRAM POSITIVE BACTERIA.Yersinia: A genus of gram-negative, facultatively anaerobic rod- to coccobacillus-shaped bacteria that occurs in a broad spectrum of habitats.Competitive Behavior: The direct struggle between individuals for environmental necessities or for a common goal.Yersinia Infections: Infections with bacteria of the genus YERSINIA.Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Physical Education and Training: Instructional programs in the care and development of the body, often in schools. The concept does not include prescribed exercises, which is EXERCISE THERAPY.Pseudomonas syringae: A species of gram-negative, fluorescent, phytopathogenic bacteria in the genus PSEUDOMONAS. It is differentiated into approximately 50 pathovars with different plant pathogenicities and host specificities.Reproduction, Asexual: Reproduction without fusion of two types of cells, mostly found in ALGAE; FUNGI; and PLANTS. Asexual reproduction occurs in several ways, such as budding, fission, or splitting from "parent" cells. Only few groups of ANIMALS reproduce asexually or unisexually (PARTHENOGENESIS).Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Staphylococcal Infections: Infections with bacteria of the genus STAPHYLOCOCCUS.Pseudomonas Infections: Infections with bacteria of the genus PSEUDOMONAS.Population Dynamics: The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.Vibrio vulnificus: A species of halophilic bacteria in the genus VIBRIO, which lives in warm SEAWATER. It can cause infections in those who eat raw contaminated seafood or have open wounds exposed to seawater.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.Poultry Diseases: Diseases of birds which are raised as a source of meat or eggs for human consumption and are usually found in barnyards, hatcheries, etc. The concept is differentiated from BIRD DISEASES which is for diseases of birds not considered poultry and usually found in zoos, parks, and the wild.Cryptococcosis: Infection with a fungus of the species CRYPTOCOCCUS NEOFORMANS.Ascomycota: A phylum of fungi which have cross-walls or septa in the mycelium. The perfect state is characterized by the formation of a saclike cell (ascus) containing ascospores. Most pathogenic fungi with a known perfect state belong to this phylum.Gene Transfer, Horizontal: The naturally occurring transmission of genetic information between organisms, related or unrelated, circumventing parent-to-offspring transmission. Horizontal gene transfer may occur via a variety of naturally occurring processes such as GENETIC CONJUGATION; GENETIC TRANSDUCTION; and TRANSFECTION. It may result in a change of the recipient organism's genetic composition (TRANSFORMATION, GENETIC).Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Rhodococcus equi: A species of RHODOCOCCUS found in soil, herbivore dung, and in the intestinal tract of cows, horses, sheep, and pigs. It causes bronchopneumonia in foals and can be responsible for infection in humans compromised by immunosuppressive drug therapy, lymphoma, or AIDS.Prophages: Genomes of temperate BACTERIOPHAGES integrated into the DNA of their bacterial host cell. The prophages can be duplicated for many cell generations until some stimulus induces its activation and virulence.Lycopersicon esculentum: A plant species of the family SOLANACEAE, native of South America, widely cultivated for their edible, fleshy, usually red fruit.Candidiasis: Infection with a fungus of the genus CANDIDA. It is usually a superficial infection of the moist areas of the body and is generally caused by CANDIDA ALBICANS. (Dorland, 27th ed)Streptolysins: Exotoxins produced by certain strains of streptococci, particularly those of group A (STREPTOCOCCUS PYOGENES), that cause HEMOLYSIS.Vibrio: A genus of VIBRIONACEAE, made up of short, slightly curved, motile, gram-negative rods. Various species produce cholera and other gastrointestinal disorders as well as abortion in sheep and cattle.Parasites: Invertebrate organisms that live on or in another organism (the host), and benefit at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Fish Diseases: Diseases of freshwater, marine, hatchery or aquarium fish. This term includes diseases of both teleosts (true fish) and elasmobranchs (sharks, rays and skates).Polysaccharides, Bacterial: Polysaccharides found in bacteria and in capsules thereof.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.4-Butyrolactone: One of the FURANS with a carbonyl thereby forming a cyclic lactone. It is an endogenous compound made from gamma-aminobutyrate and is the precursor of gamma-hydroxybutyrate. It is also used as a pharmacological agent and solvent.Streptococcus pneumoniae: A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Urinary Tract Infections: Inflammatory responses of the epithelium of the URINARY TRACT to microbial invasions. They are often bacterial infections with associated BACTERIURIA and PYURIA.Open Reading Frames: A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).Iron: A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.Amino Acid Substitution: The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Moths: Insects of the suborder Heterocera of the order LEPIDOPTERA.Francisella tularensis: The etiologic agent of TULAREMIA in man and other warm-blooded animals.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Salmonella enterica: A subgenus of Salmonella containing several medically important serotypes. The habitat for the majority of strains is warm-blooded animals.Mycobacterium tuberculosis: A species of gram-positive, aerobic bacteria that produces TUBERCULOSIS in humans, other primates, CATTLE; DOGS; and some other animals which have contact with humans. Growth tends to be in serpentine, cordlike masses in which the bacilli show a parallel orientation.Cytotoxins: Substances that are toxic to cells; they may be involved in immunity or may be contained in venoms. These are distinguished from CYTOSTATIC AGENTS in degree of effect. Some of them are used as CYTOTOXIC ANTIBIOTICS. The mechanism of action of many of these are as ALKYLATING AGENTS or MITOSIS MODULATORS.Oligonucleotide Array Sequence Analysis: Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.Mating Preference, Animal: The selection or choice of sexual partner in animals. Often this reproductive preference is based on traits in the potential mate, such as coloration, size, or behavioral boldness. If the chosen ones are genetically different from the rejected ones, then NATURAL SELECTION is occurring.Sigma Factor: A protein which is a subunit of RNA polymerase. It effects initiation of specific RNA chains from DNA.Ralstonia solanacearum: A species of Ralstonia previously classed in the genera PSEUDOMONAS and BURKHOLDERIA. It is an important plant pathogen.Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Flagella: A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called FLAGELLIN. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as CILIA but are longer in proportion to the cell bearing them and present in much smaller numbers. (From King & Stansfield, A Dictionary of Genetics, 4th ed)Cell Wall: The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.Population Density: Number of individuals in a population relative to space.Hemolysis: The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Plant Leaves: Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)Escherichia coli O157: A verocytotoxin-producing serogroup belonging to the O subfamily of Escherichia coli which has been shown to cause severe food-borne disease. A strain from this serogroup, serotype H7, which produces SHIGA TOXINS, has been linked to human disease outbreaks resulting from contamination of foods by E. coli O157 from bovine origin.Longevity: The normal length of time of an organism's life.Bacillus anthracis: A species of bacteria that causes ANTHRAX in humans and animals.Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Blood Bactericidal Activity: The natural bactericidal property of BLOOD due to normally occurring antibacterial substances such as beta lysin, leukin, etc. This activity needs to be distinguished from the bactericidal activity contained in a patient's serum as a result of antimicrobial therapy, which is measured by a SERUM BACTERICIDAL TEST.Xanthomonas: A genus in the family XANTHOMONADACEAE whose cells produce a yellow pigment (Gr. xanthos - yellow). It is pathogenic to plants.Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).Salmonella Infections: Infections with bacteria of the genus SALMONELLA.Host Specificity: The properties of a pathogen that makes it capable of infecting one or more specific hosts. The pathogen can include PARASITES as well as VIRUSES; BACTERIA; FUNGI; or PLANTS.Phagocytosis: The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.Stress, Physiological: The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.Nesting Behavior: Animal behavior associated with the nest; includes construction, effects of size and material; behavior of the adult during the nesting period and the effect of the nest on the behavior of the young.Immune Evasion: Methods used by pathogenic organisms to evade a host's immune system.Animals, Outbred Strains: Animals that are generated from breeding two genetically dissimilar strains of the same species.Cholera: An acute diarrheal disease endemic in India and Southeast Asia whose causative agent is VIBRIO CHOLERAE. This condition can lead to severe dehydration in a matter of hours unless quickly treated.Automobile Driver Examination: Government required written and driving test given to individuals prior to obtaining an operator's license.Pectobacterium chrysanthemi: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that causes vascular wilts on a wide range of plant species. It was formerly named Erwinia chrysanthemi.Aspergillus fumigatus: A species of imperfect fungi from which the antibiotic fumigatin is obtained. Its spores may cause respiratory infection in birds and mammals.Sequence Deletion: Deletion of sequences of nucleic acids from the genetic material of an individual.Pyocyanine: Antibiotic pigment produced by Pseudomonas aeruginosa.Enterococcus faecalis: A species of gram-positive, coccoid bacteria commonly isolated from clinical specimens and the human intestinal tract. Most strains are nonhemolytic.Exotoxins: Toxins produced, especially by bacterial or fungal cells, and released into the culture medium or environment.Aeromonas hydrophila: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that may be pathogenic for frogs, fish, and mammals, including man. In humans, cellulitis and diarrhea can result from infection with this organism.Viral Proteins: Proteins found in any species of virus.Clutch Size: The number of offspring produced at one birth by an oviparous or ovoviviparous animal.Sex Ratio: The number of males per 100 females.Symbiosis: The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.Metarhizium: A mitosporic fungal genus in the family Clavicipitaceae. It has teleomorphs in the family Nectriaceae. Metarhizium anisopliae is used in PESTICIDES.Physical Endurance: The time span between the beginning of physical activity by an individual and the termination because of exhaustion.Mutation Rate: The number of mutations that occur in a specific sequence, GENE, or GENOME over a specified period of time such as years, CELL DIVISIONS, or generations.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Trans-Activators: Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.Streptococcus suis: A species of STREPTOCOCCUS isolated from pigs. It is a pathogen of swine but rarely occurs in humans.Enterohemorrhagic Escherichia coli: Strains of ESCHERICHIA COLI that are a subgroup of SHIGA-TOXIGENIC ESCHERICHIA COLI. They cause non-bloody and bloody DIARRHEA; HEMOLYTIC UREMIC SYNDROME; and hemorrhagic COLITIS. An important member of this subgroup is ESCHERICHIA COLI O157-H7.Hemagglutinins: Agents that cause agglutination of red blood cells. They include antibodies, blood group antigens, lectins, autoimmune factors, bacterial, viral, or parasitic blood agglutinins, etc.Wasps: Any of numerous winged hymenopterous insects of social as well as solitary habits and having formidable stings.Hybridization, Genetic: The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.Sex: The totality of characteristics of reproductive structure, functions, PHENOTYPE, and GENOTYPE, differentiating the MALE from the FEMALE organism.Erwinia amylovora: A species of gram-negative bacteria, in the genus ERWINIA, causing a necrotic disease of plants.Genes, Fungal: The functional hereditary units of FUNGI.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Spores, Fungal: Reproductive bodies produced by fungi.Bacterial Typing Techniques: Procedures for identifying types and strains of bacteria. The most frequently employed typing systems are BACTERIOPHAGE TYPING and SEROTYPING as well as bacteriocin typing and biotyping.
... nasal colonization fitness and virulence (lung infectivity) depend on an intact competence system. ... "Addiction of Hypertransformable Pneumococcal Isolates to Natural Transformation for In Vivo Fitness and Virulence". Infect. ... "Pathogenic Properties (Virulence Factors) of Some Common Pathogens" (PDF).. *^ "Clindamycin" (PDF). Davis. 2017. Retrieved ... It has a core set of 1553 genes, plus 154 genes in its virulome, which contribute to virulence and 176 genes that maintain a ...
Vibrio regulatory RNA of OmpA
Song T, Wai SN (July 2009). "A novel sRNA that modulates virulence and environmental fitness of Vibrio cholerae". RNA Biol. 6 ( ... Little is known about how these vesicles aid virulence but it has been speculated that they may contribute by secreting toxins ... Outer membrane vesicles are secreted from the surface of gram-negative bacteria, where they are thought to aid in virulence. ... Kolling GL, Matthews KR (May 1999). "Export of virulence genes and Shiga toxin by membrane vesicles of Escherichia coli O157:H7 ...
OmpA-like transmembrane domain
Bacterial small RNA
Song T, Wai SN (July 2009). "A novel sRNA that modulates virulence and environmental fitness of Vibrio cholerae". RNA Biol. 6 ( ... Shortly after, the Staphylococcus aureus sRNA RNAIII was found to act as a global regulator of S. aureus virulence and toxin ... The FasX sRNA is the only well-characterized regulatory RNA known to control the regulation of several virulence factors in ... In some bacteria sRNAs regulate virulence genes. In Salmonella, the pathogenicity island encoded InvR RNA represses synthesis ...
reported that, among different highly transformable S. pneumoniae isolates, nasal colonization fitness and virulence (lung ... "Addiction of Hypertransformable Pneumococcal Isolates to Natural Transformation for In Vivo Fitness and Virulence". Infect. ... It has a core set of 1553 genes, plus 154 genes in its virulome, which contribute to virulence and 176 genes that maintain a ... They have a polysaccharide capsule that acts as a virulence factor for the organism; more than 90 different serotypes are known ...
"Addiction of Hypertransformable Pneumococcal Isolates to Natural Transformation for In Vivo Fitness and Virulence". Infect. ... S. pneumoniae expresses different virulence factors on its cell surface and inside the organism. These virulence factors ... of pneumococci Competence for genetic transformation likely plays an important role in nasal colonization fitness and virulence ... S. pneumoniae has several virulence factors, including the polysaccharide capsule mentioned earlier, that help it evade a ...
Carrasco P, de la Iglesia F, Elena SF (December 2007). "Distribution of fitness and virulence effects caused by single- ... Eyre-Walker A, Woolfit M, Phelps T (June 2006). "The distribution of fitness effects of new deleterious amino acid mutations in ... Sanjuán R, Moya A, Elena SF (June 2004). "The distribution of fitness effects caused by single-nucleotide substitutions in an ... Peris JB, Davis P, Cuevas JM, Nebot MR, Sanjuán R (June 2010). "Distribution of fitness effects caused by single-nucleotide ...
In turn, parasite fitness most likely depends on a trade-off between transmission (spore load) and virulence. A higher ... Thus genotype-by-genotype-by-environment (G x G x E) interactions affect fitness of the antagonists. In other words, the ... Thus, a change in a pleiotropic immunity or virulence gene can automatically affect other traits. There is thus a trade-off ... Their loss would thus decrease fitness (i.e. population growth rate). As a consequence, there is a trade-off between the ...
Virulence. 4 (5): 354-65. doi:10.4161/viru.24498. PMC 3714127 . PMID 23611873. Nadell; et al. (13 July 2011). "A fitness trade- ... Virulence genes carried within prophages as discrete autonomous genetic elements, known as morons, confer an advantage to the ... On the other hand, the prophage may transfer genes that enhance host virulence and resistance to the immune system. Also, the ... In this way, temperate bacteriophages also play a role in the spread of virulence factors, such as exotoxins and exoenzymes, ...
"Distribution of fitness and virulence effects caused by single-nucleotide substitutions in Tobacco Etch virus". Journal of ... By effect on fitnessEdit. See also: Fitness (biology). In applied genetics, it is usual to speak of mutations as either harmful ... Distribution of fitness effectsEdit. Attempts have been made to infer the distribution of fitness effects (DFE) using ... It is believed that the overwhelming majority of mutations have no significant effect on an organism's fitness.[better ...
The virulence of the virus may be changed, for example, or a virus could evolve to become adapted to a different host ... Quantitative Modeling of Virus Evolutionary Dynamics and Adaptation in Serial Passages Using Empirically Inferred Fitness ... Changing the virulence of SARS in this way was important, because without a virulent form of SARS to infect laboratory animals ... These attempts increased the virulence of the virus. Then, he realized that he could put dog tissue into a monkey to infect it ...
Methicillin-resistant Staphylococcus aureus
In contrast, CA-MRSA tends to carry lower fitness cost SCCmec elements to offset the increased virulence and toxicity ... in 2001 and can be explained by the fitness differences associated with carriage of a large or small SCCmec plasmid. Carriage ... The arginine catabolic mobile element (ACME) is a virulence factor present in many MRSA strains but not prevalent in MSSA. SpeG ... Diep BA, Carleton HA, Chang RF, Sensabaugh GF, Perdreau-Remington F (2006). "Roles of 34 virulence genes in the evolution of ...
Bacteriophage experimental evolution
Virulence is the negative impact that a pathogen (or parasite) has on the Darwinian fitness of a harboring organism (host). For ... Variable Pleiotropic Effects From Mutations at the Same Locus Hamper Prediction of Fitness From a Fitness Component. Genetics ... The older phage literature contains numerous references to phage virulence, and phage virulence evolution. However, the reader ... The older phage literature contains numerous references to phage virulence, and phage virulence evolution. However, the reader ...
Parasite increased trophic transmission
A high virulence in the wolf is unfavorable if it decreases predator abilities. Thus, the tapeworm's fitness is increased by a ... High virulence that results in the death of an intermediate host before it can be preyed upon by a definitive host is ... The parasite therefore needs to evolve different levels of virulence at different life stages in different hosts. Parasite ... This subsequently reduces the risk infection to the host's kin, and therefore increases the host's inclusive fitness. Another ...
Plant disease resistance
Breeding efforts continue because pathogen populations are under selection pressure for increased virulence, new pathogens ... gene followed the finding that avrBs2 is found in most disease-causing Xanthomonas species and is required for pathogen fitness ... effectors are DNA-binding proteins that activate host gene expression to enhance pathogen virulence. Both the rice and pepper ... "Role of Ubiquitination in Plant Innate Immunity and Pathogen Virulence". Journal of Plant Biology. 53 (1): 10-18. doi:10.1007/ ...
Unit of selection
... where the fitness of the group is higher or lower than the mean fitness of the constituent individuals, group selection can be ... "lower virulence", i.e., "virulence" is presented as a group trait. One could argue then that the selection is in fact against ... In this case, however, the fitness of all viruses within a rabbit is affected by what the group does to the rabbit. Indeed, the ... If a relatively faster gazelle manages to survive and reproduce more, the causation of the higher fitness of this gazelle can ...
Hence, phenotypic plasticity can evolve if Darwinian fitness is increased by changing phenotype. However, the fitness benefits ... Commonly, invertebrates respond to parasitic castration or increased parasite virulence with fecundity compensation in order to ... "Latitudinal patterns in phenotypic plasticity and fitness-related traits: assessing the climatic variability hypothesis (CVH) ... "The costs of mounting an immune response are reflected in the reproductive fitness of the mosquito Anopheles gambiae". Oikos. ...
... ability or lack thereof of a pathogen to adapt to its host environment is an indicator of the pathogen's fitness or virulence. ... If a pathogen has high fitness in the host environment, or is virulent, it will be able to grow and spread quickly within its ... The pH of the Host Niche Controls Gene Expression in and Virulence of Candida albicans. Infect. Immun. July 1998 vol. 66 no. 7 ... Pathogens like Salmonella, which is a food borne pathogen, are able to adapt to the host environment and maintain virulence via ...
Targeted mutation of the ftrA gene did not induce a decrease in virulence in the murine model of A. fumigatus invasion. In ... have been shown to impact the fitness of A. fumigatus in hypoxic conditions. The transcription factor SrbA is the master ... A number of studies found that the unfolded protein response contributes to virulence of A. fumigatus. ... Many of the genes involved in such processes have been shown to impact virulence through experiments involving genetic mutation ...
Mobile genetic elements
One of the examples of MGEs in evolutionary context is that virulence factors and antibiotic resistance genes of MGEs can be ... Newly acquired genes though this mechanism can increase fitness by gaining new or additional functions. On the other hand, MGEs ... This is a mechanism of horizontal gene transfer that bacteria can share virulence factors and antibiotic resistance genes. ... Classification of mobile genetic elements Horizontal gene transfer Virulence factors Mu, X.; Ahmad, S.; Hur, S. Endogenous ...
Virulence (the tendency of a pathogen to cause damage to a host's fitness) evolves when that pathogen can spread from a ... Definitions: pathogenicity vs virulence; incidence vs prevalence". COLOSS. Carl Nathan (2015-10-09). "From transient infection ... Pathogenicity is related to virulence in meaning, but some authorities have come to distinguish it as a qualitative term, ... Such comparisons are described instead in terms of relative virulence. Pathogenicity is also distinct from the transmissibility ...
A variety of virulence factors were analysed in Pseudomonas aeruginosa strains isolated from pneumonia patients. Rhamnolipids ... The anti-microbial action of rhamnolipids may provide a fitness advantage for Pseudomonas aeruginosa by excluding other ... In summary, rhamnolipids have been shown unequivocally to be a potent virulence factor in the human host, however, they are ... Zulianello L, Canard C, Köhler T, Caille D, Lacroix JS, Meda P (June 2006). "Rhamnolipids are virulence factors that promote ...
One definition of virulence is the host's parasite-induced loss of fitness. The parasite's fitness is determined by its success ... Any movement on the virulence axis, towards higher or lower virulence, will result in lower fitness for the parasite, and thus ... virulence. The idea is, then, that there exists an equilibrium point of virulence, where parasite's fitness is highest. ... The evolution of virulence in pathogens is a balance between the costs and benefits of virulence to the pathogen. For example, ...
... virulence can be defined as the host's parasite-induced loss of fitness. Virulence can be understood in terms of proximate ... The pathogenicity of an organism - its ability to cause disease - is determined by its virulence factors. The noun virulence ... This is because the fitness of the host is bound to the fitness in vertical transmission but is not so bound in horizontal ... and intrinsic characteristics of the bacteria called virulence factors. Many virulence factors are so-called effector proteins ...
In fact, studies involving mutation of genes coding for protein A resulted in a lowered virulence of S. aureus as measured by ... Clauditz A, Resch A, Wieland KP, Peschel A, Götz F (August 2006). "Staphyloxanthin plays a role in the fitness of ... This pigment acts as a virulence factor, primarily by being a bacterial antioxidant which helps the microbe evade the reactive ... Patel AH, Nowlan P, Weavers ED, Foster T (December 1987). "Virulence of protein A-deficient and alpha-toxin-deficient mutants ...
Selectional pleiotropy occurs when the resulting phenotype has many effects on fitness (depending on factors such as age and ... Since a single toxin gene or virulence allele can grant the ability to colonize the host, adaptation and reproductive isolation ... This mathematical model illustrates how evolutionary fitness depends on the independence of phenotypic variation from random ... Williams suggested that some genes responsible for increased fitness in the younger, fertile organism contribute to decreased ...
DNA adenine methylation is important in bacteria virulence in organisms such as Escherichia coli, Salmonella, Vibrio, Yersinia ... They control gene expression including virulence genes in pathogens and are viewed as new targets in the fight against drug- ... Fitness landscape/evolutionary landscape. *Pleiotropy. *Plasticity. *Polygenic inheritance. *Transgressive segregation. * ... "A random six-phase switch regulates pneumococcal virulence via global epigenetic changes". Nature Communications. 5: 5055. PMC ...
Pandemic H1N1/09 virus
VirulenceEdit. Virulence (the tendency of a pathogen to reduce a host's fitness) evolves when a pathogen can spread from a ... Evolutionary biology proposes that many pathogens evolve an optimal virulence at which the fitness gained by increased ... Definitions: pathogenicity vs virulence; incidence vs prevalence". COLOSS. Archived from the original on 2017-04-24. Retrieved ... Pathogenicity is related to virulence in meaning, but some authorities have come to distinguish it as a qualitative term, ...
Newport, contributes to the strain's fitness in tomatoes, and has homologs in genomes of other Enterobacteriaceae that are able ... mgtC leader RNA from bacteria virulence gene (mgtCBR operon) decreases flagellin production during infection by directly base ... "Role of the RecBCD recombination pathway in Salmonella virulence". Journal of Bacteriology. 184 (2): 592-5. doi:10.1128/jb. ... "Role of acid tolerance response genes in Salmonella typhimurium virulence". Infection and Immunity. 61 (10): 4489-92. doi ...
Red Queen hypothesis
... increase in fitness) of one species deteriorates the fitness of coexisting species, but because coexisting species evolve as ... "Bacterial predator-prey coevolution accelerates genome evolution and selects on virulence-associated prey defences", Nature ... well, no one species gains a long-term increase in fitness, and the overall fitness of the system remains constant. The ... in which each speciation event in a clade deteriorates the fitness of coexisting species in the same clade (provided that there ...
Although most mycoviruses often do not seem to disturb their host's fitness, this does not necessarily mean they are living ... May, R. M.; Nowak, M. A. (1995). "Coinfection and the evolution of parasite virulence" (PDF). Proceedings of the Royal Society ... In summary, the main negative effects of mycoviruses are: Decreased growth rate Lack of sporulation Attenuation of virulence ... Chen, B.; Choi, G. H.; Nuss, D. L. (1994). "Attenuation of fungal virulence by synthetic infectious hypovirus transcripts". ...
The C-terminus of the NLRs consists of a leucine-rich repeat (LRR) motif, which is involved in sensing the pathogen virulence ... which substantially reduces the fitness of the offspring and gene flow to subsequent generations. ... Direct binding of the virulence factors to the NLRs can result in the activation of HR. However, this seems to be quite rare. ... The identification of a pathogen typically occurs when a virulence gene product, secreted by a pathogen, binds to, or ...
Bacteriophages may harbour virulence factors or toxic genes in their genomes and identification of genes with similarity to ... Additional mutations, however, may compensate for this fitness cost and can aid the survival of these bacteria. ... Antibacterial resistance may impose a biological cost, thereby reducing fitness of resistant strains, which can limit the ... known virulence factors or toxins by genomic sequencing may be prudent prior to use. In addition, the oral and IV ...
... encoding genes that sometimes give them an increased virulence. An example of this is the pox virus vaccinia which encoded a ... exhibit genetic drift over time but the amount that they are able to drift without occurring a negative impact on their fitness ... Many of the proteins known to show antigenic or phase variation are related to virulence. ...
2003). "Mosquito mortality and the evolution of malaria virulence". Evolution. 57 (12): 2792-804. doi:10.1554/03-211. PMID ... The survivorship and relative fitness of mosquitoes are not adversely affected by Plasmodium infection, which indicates the ... importance of vector fitness in shaping the evolution of Plasmodium. Plasmodium has evolved the capability to manipulate ...
Virulence. Virulence (the tendency of a pathogen to cause damage to a host's fitness) evolves when that pathogen can ... Definitions: pathogenicity vs virulence; incidence vs prevalence". COLOSS.. *^ Carl Nathan (2015-10-09). "From transient ... Pathogenicity is related to virulence in meaning, but some authorities have come to distinguish it as a qualitative term, ... A bacterium may participate in opportunistic infections in immunocompromised hosts, acquire virulence factors by plasmid ...
Host fitness. Single host, stays alive. Single host, dies. Multiple hosts Able to. reproduce. (fitness , 0). Conventional ... Competition favoring virulence. Competition between parasites can be expected to favour faster reproducing and therefore ... fitness = 0). -----. Parasitic castrator. Trophically transmitted parasitic castrator. Parasitoid. Social predator[b]. Solitary ... Among competing parasitic insect-killing bacteria of the genera Photorhabdus and Xenorhabdus, virulence depended on the ...
... aiding in the evasion of host immune defenses and thus contributing to the virulence of these bacterial strains. ... TLR4-TRIF Innate Immune Signaling in Hematopoietic Stem Cells Promotes Proliferation but Reduces Competitive Fitness". Cell ... which may also contain other virulence factors and proteins. ... Virulence. factor. *Clumping factor A. *Fibronectin binding ...
Human genetic resistance to malaria
Fitnesses of different genotypes. The fitnesses of different genotypes in an African region where there is intense ... virulence factors - enable an infectious agent to replicate and disseminate within a host in part by subverting or eluding host ... so fitness calculations will also vary. In many African populations the AS frequency is about 20%, and a fitness superiority ... fitness (genetic) - loosely, reproductive success that tends to propagate a trait or traits (see natural selection) ...
Ben-Ami, F.; Rigaud, T.; Ebert, D. (2011-06-01). "The expression of virulence during double infections by different parasites ... The infection leads to reduction in the host fitness by reducing life expectancy, fecundity and competitive ability for ... Mangin, K. L.; M. Lipsitch & D. Ebert (1995). "Virulence and transmission modes of two microsporidia in Daphnia magna". ... Bieger, Annette; Ebert, Dieter (2009-05-01). "Expression of parasite virulence at different host population densities under ...
Tn-seq is useful for both the study of a single gene's fitness as well as gene interactions Signature-tagged mutagenesis (STM) ... 2012). "Control of virulence by small RNAs in Streptococcus pneumoniae". PLoS Pathogens. 8: e1002788. doi:10.1371/journal.ppat. ... Tn-seq can be used to identify both the fitness of single genes and to map gene interactions in microorganisms. Existing ... 2009). "Tn-seq: highthroughput parallel sequencing for fitness and genetic interaction studies in microorganisms". Nature ...
Fluoroquinolone Resistance in Salmonella: Mechanisms, Fitness, and Virulence | IntechOpen
... and the acquisition of fluoroquinolone resistance might have significant influences on the bacterial fitness and virulence. Due ... 4. Virulence. There is an increase in the knowledge about the virulence mechanisms of Salmonella which led to a broad study of ... Fluoroquinolone Resistance in Salmonella: Mechanisms, Fitness, and Virulence. By Jun Li, Haihong Hao, Abdul Sajid, Heying Zhang ... investigating the virulence of nalidixic acid-resistant strain of Salmonella Typhimurium, they found that the virulence was ...
YbeY Is Essential For Fitness And Virulence Of V. Cholerae, Keeps RNA Household In Order - Redorbit
YbeY Is Essential For Fitness And Virulence Of V. Cholerae, Keeps RNA Household In Order. by editor ... In addition, they find that YbeY targets virulence-associated small regulatory RNAs. Consistent with these functions, reducing ... critical for cell fitness and general stress tolerance, and involved in the regulation of different classes of RNA targets. ... and its ability to sensitize pathogens by disrupting stress tolerance and virulence, a YbeY-specific antibiotic could have ...
Fitness and virulence of antibiotic resistant bacteria.
Experimental viral evolution to specific host MHC genotypes reveals fitness and virulence trade-offs in alternative MHC types |...
Pathogen fitness is positively correlated with virulence. Regression analyses between measures of pathogen fitness and ... across the three host genotypes shows that pathogen fitness and virulence is host genotype-specific. Viral fitness (12 of 12 ... Experimental viral evolution to specific host MHC genotypes reveals fitness and virulence trade-offs in alternative MHC types. ... Pathogens adapt to specific MHC genotypes, and this results in lower fitness and virulence when infecting unfamiliar MHC ...
Association of the outer membrane protein Omp33 with fitness and virulence of Acinetobacter baumannii
However, the role of Omp33 in the fitness and virulence of A. baumannii remains unknown. In the present study, we investigated ... the role of Omp33 in fitness and virulence of … ... However, the role of Omp33 in the fitness and virulence of A. ... Association of the outer membrane protein Omp33 with fitness and virulence of Acinetobacter baumannii J Infect Dis. 2013 Nov 15 ... In the present study, we investigated the role of Omp33 in fitness and virulence of A. baumannii by using an isogenic knockout ...
Impact of AmpC Derepression on Fitness and Virulence: the Mechanism or the Pathway? | mBio
... had no fitness-virulence cost. Further analysis indicated that fitness-virulence impairment is caused by overexpressing ampC in ... Likewise, reduced fitness is expected to directly impair bacterial virulence, but the interplay between virulence and ... The virulence genes studied were exoS (A), lasA (B), pcrV (C), plcB (D), pilM (E), and pscH (F). The results of the virulence ... Impact of AmpC Derepression on Fitness and Virulence: the Mechanism or the Pathway?. Marcelo Pérez-Gallego, Gabriel Torrens, ...
Frontiers | Prophage Rs551 and Its Repressor Gene orf14 Reduce Virulence and Increase Competitive Fitness of Its Ralstonia...
... expression of targeted virulence and virulence regulatory genes (pilT, egl, pehC, hrPB, and phcA), and virulence, suggesting ... expression of targeted virulence and virulence regulatory genes (pilT, egl, pehC, hrPB, and phcA), and virulence, suggesting ... In this study, we determined the effect of the prophage and its ORF14 on the virulence and competitive fitness of its carrier ... ϕRs551 may play an important role by regulating the virulence of and offering a competitive fitness advantage to its carrier ...
Frontiers | Decreased Fitness and Virulence in ST10 Escherichia coli Harboring blaNDM-5 and mcr-1 against a ST4981 Strain with...
... potentially contributing to increased virulence of GZ3. Decreased fitness and virulence in a mcr-1 and blaNDM-5 co-harboring ... little is known about the fitness and virulence of such strains. Three carbapenem-resistant Escherichia coli (GZ1, GZ2 and GZ3 ... successively isolated from one patient in 2015 were investigated for microbiological fitness and virulence. GZ1 and GZ2 were ... successively isolated from one patient in 2015 were investigated for microbiological fitness and virulence. GZ1 and GZ2 were ...
Enhanced in planta Fitness through Adaptive Mutations in EfpR, a Dual Regulator of Virulence and Metabolic Functions in the...
... that several independent single mutations in the efpR gene from populations propagated on beans were associated with fitness ... Enhanced in planta Fitness through Adaptive Mutations in EfpR, a Dual Regulator of Virulence and Metabolic Functions in the ... EfpR also controls virulence traits such as exopolysaccharide production, swimming and twitching motilities and deletion of ... Altogether, these results indicated that EfpR is a novel central player of the R. solanacearum virulence regulatory network. ...
Resistance to Alpha/Beta Interferon Is a Determinant of West Nile Virus Replication Fitness and Virulence | Journal of Virology
Resistance to Alpha/Beta Interferon Is a Determinant of West Nile Virus Replication Fitness and Virulence. Brian C. Keller, ... Control of IFN-α/β signaling is a determinant of WNV replication fitness in vitro and of virulence in vivo.Since MAD78 is ... Our data show that viral control of IFN action and JAK-STAT signaling is critical for high replication fitness and virulence. ... Resistance to Alpha/Beta Interferon Is a Determinant of West Nile Virus Replication Fitness and Virulence ...
A functional tonB gene is required for both virulence and competitive fitness in a chinchilla model of Haemophilus influenzae...
An insertional mutation in tonB was constructed and the impact of the mutation on virulence and fitness in a chinchilla model ... The tonB insertion mutant strain was significantly impacted in both virulence and fitness as compared to the wildtype strain in ... An insertional mutation in tonB was constructed and the impact of the mutation on virulence and fitness in a chinchilla model ... A functional tonB gene is required for both virulence and competitive fitness in a chinchilla model of Haemophilus influenzae ...
Draft genome sequence of Actinotignum schaalii DSM 15541T: Genetic insights into the lifestyle, cell fitness and virulence -...
Draft genome sequence of Actinotignum schaalii DSM 15541T: Genetic insights into the lifestyle, cell fitness and virulence. ... Draft genome sequence of Actinotignum schaalii DSM 15541T: Genetic insights into the lifestyle, cell fitness and virulence ... A. schaalii genome also encodes several virulence factors that contribute to adhesion and internalization of this pathogen such ...
Virulence-transmission trade-offs and population divergence in virulence in a naturally occurring butterfly parasite | PNAS
Plotting fitness estimates ωe and ωl against parasite spore load reveals concave fitness curves (Fig. 3) generated by a trade- ... Parasite Lifetime Fitness.. We calculated two measures of parasite lifetime fitness (ω) as a function of spore load (p) by ... Theory predicts that parasites could evolve virulence (i.e., parasite-induced reductions in host fitness) by balancing the ... Virulence-transmission trade-offs and population divergence in virulence in a naturally occurring butterfly parasite. Jacobus C ...
Investigating the role of prophage on mycobacterial host fitness and virulence - Maine INBRE
Investigating the role of prophage on mycobacterial host fitness and virulence. Project Summary. Diseases caused by ... This project aims to characterize the impact of prophage on mycobacterial fitness and virulence by exploring the role of ... Investigating the role of prophage on mycobacterial host fitness and virulence. ... many of the most significantly upregulated genes in pathogenic mycobacteria potentially play roles in host fitness or virulence ...
Regulation Of Fitness And Virulence In Oral Streptococci - Ping Xu
Regulation Of Fitness And Virulence In Oral Streptococci Xu, Ping Virginia Commonwealth University, Richmond, VA, United States ... Regulation Of Fitness And Virulence In Oral Streptococci. Xu, Ping / Virginia Commonwealth University. $368,285. ... Regulation Of Fitness And Virulence In Oral Streptococci. Xu, Ping / Virginia Commonwealth University. $312,282. ... Regulation Of Fitness And Virulence In Oral Streptococci. Xu, Ping / Virginia Commonwealth University. $50,066. ...
OPUS 4 | Tackling the Regulation of Pneumococcal Fitness and Virulence Factors
The TIGR4Δrr08, and all TCS08 mutants in D39 showed a decrease in virulence in the pneumonia model, with no changes in sepsis. ... Specifically, those coding for the adhesins PavB and PI-1 and fitness proteins from the cel, arc and fab operons. Remarkably, ... Interestingly, important pneumococcal virulence determinants show variations in the gene and protein sequence among the ... Es kann zusammengefasst werden, dass das TCS08 von S. pneumoniae die Expression von Genen, welche an der Fitness und ...
i,oryzae,/i, contribute to full fitness in rice by regulating virulence factors expression . Opens in a new window. ... oryzae contribute to full fitness in rice by regulating virulence factors expression *Dehong Zheng ... Nematicidal spore-forming Bacilli share similar virulence factors and mechanisms *Ziqiang Zheng ... Rights & permissionsfor article Nematicidal spore-forming Bacilli share similar virulence factors and mechanisms . Opens in a ...
Complete nucleotide sequence of pRS218, a large virulence plasmid, that augments pathogenic potential of meningitis-associated...
Plasmid genes are color coded as follows: Blue, conjugal transfer genes; Green, virulence or fitness-associated genes; Orange, ... Evaluation of virulence potential of pRS218 in vitro and in vivo. A, Involvement of pRS218 in invasion of hCMEC cells. B, ... and contains a genetic load region that encodes several virulence and fitness traits such as enterotoxicity, iron acquisition ... Comparison of pRS218 sequence to some virulence plasmids of other E. coli . Each code indicates a plasmid sequence. From top to ...
A Zika virus envelope mutation preceding the 2015 epidemic enhances virulence and fitness for transmission - PubMed
A Zika virus envelope mutation preceding the 2015 epidemic enhances virulence and fitness for transmission Chao Shan 1 2 , ... A Zika virus envelope mutation preceding the 2015 epidemic enhances virulence and fitness for transmission Chao Shan et al. ... Overall, our study revealed E-V473M as a critical determinant for enhanced ZIKV virulence, intrauterine transmission during ... competition experiments in cynomolgus macaques showed that this mutation increased its fitness for viremia generation, ...
UN Chief Vows to Help Haiti End Cholera Epidemic
Pneumonia-Specific Escherichia coli with Distinct Phylogenetic and Virulence Profiles, France, 2012-2014 - Volume 25, Number 4...
Virulence factor gene content and antimicrobial drug resistance were higher in pneumonia than in commensal isolates. Genomic ... Pneumonia isolates carried higher proportions of virulence genes sfa/foc, papGIII, hlyC, cnf1, and iroN compared with ... and virulence factor gene content. We compared 260 isolates with those of 2 published collections containing commensal and ... Bleibtreu A, Gros P-A, Laouénan C, Clermont O, Le Nagard H, Picard B, et al. Fitness, stress resistance, and extraintestinal ...
Determination of virulence and fitness genes associated with the pheU, pheV and selC integration sites of LEE-negative food...
Determination of virulence and fitness genes associated with the pheU, pheV and selC integration sites of LEE-negative food- ... A virulence type IV toxin-antitoxin system was detected in three strains. Additionally, the ato system was found in one strain ... Results: In total, 293 open reading frames partially encoding putative virulence factors such as TonB-dependent receptors, DNA ... The island contained integrases and mobile elements in addition to genes for increased fitness and those playing a putative ...
Harbouring public good mutants within a pathogen population can increase both fitness and virulence | India Environment Portal ...
Harbouring public good mutants within a pathogen population can increase both fitness and virulence. Harbouring public good ... Harbouring public good mutants within a pathogen population can increase both fitness and virulence ... mutants within a pathogen population can increase both fitness and virulence. Existing theory, empirical, clinical and field ... In vivo infections of rice demonstrate that M. oryzae virulence is enhanced, quite paradoxically, when a public good mutant is ...
Indole-3-acetic acid in plant-pathogen interactions: a key molecule for in planta bacterial virulence and fitness | IRIS...
Indole-3-acetic acid in plant-pathogen interactions: a key molecule for in planta bacterial virulence and fitness. ... Indole-3-acetic acid in plant-pathogen interactions: a key molecule for in planta bacterial virulence and fitness ... metabolism and drug resistance confirmed the presence of a concerted regulatory network in this phytopathogen among virulence, ... metabolism and drug resistance confirmed the presence of a concerted regulatory network in this phytopathogen among virulence, ...
Current Protein & Peptide Science, Volume 18 - Number 11
Optimal virulence - Wikipedia
One definition of virulence is the hosts parasite-induced loss of fitness. The parasites fitness is determined by its success ... Any movement on the virulence axis, towards higher or lower virulence, will result in lower fitness for the parasite, and thus ... virulence. The idea is, then, that there exists an equilibrium point of virulence, where parasites fitness is highest. ... The evolution of virulence in pathogens is a balance between the costs and benefits of virulence to the pathogen. For example, ...
The Concept of Fitness in Leishmania | SpringerLink
A pathogens fitness relates to all biological processes that ensure its survival, reproduction, and transmission in specific ... Fitness determinants Drug resistance Virulence Leishmaniasis Parasite fitness Fitness cost This is a preview of subscription ... this may contrast with the usual fitness cost observed in natural drug-resistant organisms and highlights parasite fitness as ... Practical applications of viral fitness in clinical practice. Curr Opin Infect Dis. 2003;16:11-8.PubMedCrossRefGoogle Scholar ...
Table of Contents - January 07, 2015, 282 (1798) | Proceedings of the Royal Society of London B: Biological Sciences
Serial infection of diverse host (Mus) genotypes rapidly impedes pathogen fitness and virulence. ... Direct and indirect causal effects of heterozygosity on fitness-related traits in Alpine ibex. ... Eyespots deflect predator attack increasing fitness and promoting the evolution of phenotypic plasticity. ...
Community Ebola Modeling Phone Call - Eclipsepedia
Discussed two definitions: Virulence vs infectivity * Virulence - mortality, morbidity. * Infectivity - basic reproduction ... Dont know the impact on fitness. * Virus mutation rate is accelerating * Rate is twice the mutation rate before this outbreak ... Some may have better some worse fitness. * Current outbreak, most common ancestor is 2007/2008 Congo outbreak * Absolute parent ... 20 minute deep dive topic: Ebola Deep-Dive Topic: Mutation and Fitness Landscape * Ebola 2014 Mutation Rate: Comparison to ...
JCI - Gene fitness landscape of group A streptococcus during necrotizing myositis
Genes encoding many documented virulence factors or virulence-modulating factors were identified as contributing to fitness in ... In addition to metabolic genes, several previously identified GAS virulence or fitness factors were also among the 72 genes. ... Genome-wide discovery of novel M1T1 group A streptococcal determinants important for fitness and virulence during soft-tissue ... For example, ScfAB (2 putative membrane proteins) was identified as important for GAS fitness and virulence during subcutaneous ...
GenesPathogenPathogensEvolution of virulencePathogenesisToxinsAnti-virulenceExplored the relationship between virulenceInfectionMutationsEvolutionaryChange in virulenceContribute to virulenceInterference with virulenceMechanismLower virulenceAttenuates virulenceHigh-virulenceAlter virulenceHigher virulenceVitroPseudomonasAntibiotic resistanPlasmidsPopulationsViral fitnessReductionParasite-inducedInfectionsIncreasesParasite'sReplicationGeneticBacteremiaDeletion
- In this study, we determined the effect of the prophage and its ORF14 on the virulence and competitive fitness of its carrier strain UW551 by deleting the orf14 gene only (the UW551 orf14 mutant), and nine of the prophage's 14 genes including orf14 and six out of seven structural genes (the UW551 prophage mutant), respectively, from the genome of UW551. (frontiersin.org)
- The two mutants were increased in extracellular polysaccharide production, twitching motility, expression of targeted virulence and virulence regulatory genes ( pilT, egl, pehC, hrPB, and phcA ), and virulence, suggesting that the virulence of UW551 was negatively regulated by ϕRs551, at least partially through ORF14. (frontiersin.org)
- Whole genome sequence analysis revealed that 28 virulence genes were specific to GZ3, potentially contributing to increased virulence of GZ3. (frontiersin.org)
- Lysogenic phage are capable of inserting their genome into that of the bacterial hosts, often carrying genes that add function to the host cell leading to increased bacterial fitness and pathogenicity. (maineidea.net)
- however, we have found that many of the most significantly upregulated genes in pathogenic mycobacteria potentially play roles in host fitness or virulence. (maineidea.net)
- Real-time quantitative PCR experiments suggest that Mgs regulates several putative virulence genes. (grantome.com)
- Interestingly, the genes encoding the glycolytic protein enolase and the toxin pneumolysin were the most conserved virulence determinants. (uni-greifswald.de)
- Pneumonia isolates carried higher proportions of virulence genes sfa/foc , papGIII , hlyC , cnf1 , and iroN compared with bacteremia isolates. (cdc.gov)
- The island contained integrases and mobile elements in addition to genes for increased fitness and those playing a putative role in pathogenicity. (rki.de)
- Gene expression analysis of several genes related to TTSS, IAA metabolism and drug resistance confirmed the presence of a concerted regulatory network in this phytopathogen among virulence, fitness and drug efflux. (unifi.it)
- It has a core set of 1553 genes , plus 154 genes in its virulome, which contribute to virulence and 176 genes that maintain a noninvasive phenotype . (wikipedia.org)
- Quorum sensing is a cell density-dependent signaling phenomenon used by bacteria for coordination of population-wide phenotypes, such as expression of virulence genes, antibiotic resistance and biofilm formation. (mdpi.com)
- This island carried genes potentially associated with virulence and fitness. (sigmaaldrich.com)
- CA-MRSA clinical isolates (USA300) differing in the presence or absence of ACME and a USA300 wild-type/ACME deletion mutant pair were analyzed for in vitro expression of global regulatory genes and production of virulence factors. (asm.org)
- There was no significant difference in the expression of selected genes mediating virulence ( hla , lukSF-PV , agr , saeRS ) among the isolates tested, regardless of the presence of ACME. (asm.org)
- The expression of virulence genes in one nisin-resistant mutant and two class IIa bacteriocin-resistant mutants of the same wild-type strain was analyzed, and each mutant consistently showed either an increase or a decrease in the expression of virulence genes ( prfA -regulated as well as prfA -independent genes). (asm.org)
- A highly clonal lineage, which experimentally shows reduced fitness, has undergone pseudogenization in genes required for virulence and morphogenesis, which may explain its niche restriction. (nature.com)
- Other sets of compounds have been used to block the transcription of virulence factor genes in enteropathogenic Escherichia coli ( 14 ) and Vibrio cholerae ( 20 ). (asm.org)
- Several genes needed for virulence in mammals are also required for pathogenesis in C. elegans ( 2 , 10 , 16 , 28 ), implying that the invasion and proliferation of serovar Typhimurium in the host intestine depend on mechanisms common to the nematode and mammals. (asm.org)
- GGS_124 and GAS, but not other streptococci, shared a number of virulence factor genes, including genes encoding streptolysin O, NADase, and streptokinase A, distantly related to SIC (DRS), suggesting the importance of these factors in the development of invasive disease. (biomedsearch.com)
- All 3 prophages were significantly similar to GAS prophages that carry virulence factor genes, indicating that these prophages had transferred these genes between pathogens. (biomedsearch.com)
- SDSE was found to contain a gene encoding a superantigen, streptococcal exotoxin type G, but lacked several genes present in GAS that encode virulence factors, such as other superantigens, cysteine protease speB, and hyaluronan synthase operon hasABC. (biomedsearch.com)
- CRISPR spacers may limit the horizontal transfer of phage encoded GAS virulence genes into SDSE. (biomedsearch.com)
- Turning to Vibrio cholerae to examine the role of YbeY in disease-causing pathogens, they now report that YbeY is essential in this pathogen, critical for cell fitness and general stress tolerance, and involved in the regulation of different classes of RNA targets. (redorbit.com)
- These data are unique in experimentally confirming the requisite conditions of the antagonistic coevolution model of MHC evolution and providing quantification of fitness effects for pathogen and host. (pnas.org)
- i ) adaptations that benefit pathogen fitness in one host MHC genotype must be costly to pathogen fitness when infecting hosts carrying an unfamiliar MHC genotype (i.e., antagonistic pleiotropy), and ( ii ) these patterns of adaptation must produce correlated patterns of virulence (i.e., disease severity). (pnas.org)
- These fitness trade-offs, which arise as a consequence of pathogen adaptation to specific MHC genotypes, provides a selective advantage to hosts carrying unfamiliar (i.e., rare) MHC genotypes through increased resistance to infectious disease. (pnas.org)
- Experimental evolution of the plant pathogen Ralstonia solanacearum, where bacteria were maintained on plant lineages for more than 300 generations, revealed that several independent single mutations in the efpR gene from populations propagated on beans were associated with fitness gain on bean. (nih.gov)
- At one time, some biologists argued that pathogens would tend to evolve toward ever decreasing virulence because the death of the host (or even serious disability) is ultimately harmful to the pathogen living inside. (wikipedia.org)
- The evolution of virulence in pathogens is a balance between the costs and benefits of virulence to the pathogen. (wikipedia.org)
- Existing theory, empirical, clinical and field research all predict that reducing the virulence of individuals within a pathogen population will reduce the overall virulence, rendering disease less severe. (org.in)
- campestris resulted in the failure of the pathogen to grow in medium with pyruvate or C 4 -dicarboxylates as the sole carbon source and a significant reduction in virulence, indicating that X. campestris pv. (asm.org)
- The PhcA virulence regulator in the vascular wilt pathogen Ralstonia solanacearum responds to cell density via quorum sensing. (asm.org)
- Hysteretic switching between virulence states has been observed in a human pathogen. (elifesciences.org)
- A fungal effector secreted by the corn smut pathogen increases the virulence of the pathogen by elevating anthocyanin production and reducing lignification in maize. (elifesciences.org)
- The acquisition of a virulence plasmid is sufficient to turn a beneficial strain of Rhodococcus bacteria into a pathogen. (elifesciences.org)
- Here, we experimentally address how parasite relatedness affects virulence of a bacterial pathogen when competition can result in one strain exploiting resource-scavenging molecules produced by another. (biomedcentral.com)
- Acquired antibiotic resistance in V. cholerae draws attention to the development of novel therapeutics that counteract virulence, rather than the viability of the pathogen. (usda.gov)
- Virulence is a pathogen or microbe's ability to infect or damage a host. (wikipedia.org)
- Virulence can be understood in terms of proximate causes-those specific traits of the pathogen that help make the host ill-and ultimate causes-the evolutionary pressures that lead to virulent traits occurring in a pathogen strain. (wikipedia.org)
- Here, we examined the contribution of IreA to growth and virulence in the human fungal pathogen Aspergillus fumigatus . (prolekare.cz)
- By contrast, the filamentous fungal pathogen Aspergillus fumigatus is predominantly extracellular, with no known virulence factors that are specialized derivatives of the secretory pathway. (prolekare.cz)
- MgAtr4 is the first virulence factor cloned from this important plant pathogen. (apsnet.org)
- These phenotypes enhance virulence, but it is not clear whether they play a dominant role in specific pathogen-host interactions. (asm.org)
- The best-studied virulence-associated factors are the effector proteins secreted through the type III secretion system, which both restrict and promote specific pathogen-host interactions ( 1 , 21 , 26 , 30 , 45 ). (asm.org)
- We studied the relationship between virulence (ability to kill nondormant Bromus tectorum seeds) and mycelial growth index in the necrotrophic seed pathogen Pyrenophora semeniperda. (usda.gov)
- Seed pathosystems involving necrotrophs differ from those commonly treated in traditional evolution-of-virulence models in that host death increases pathogen fitness by preventing. (usda.gov)
- It also analyzes the structure of virulence in populations of a pathogen, and demonstrates how virulence can be deliberately restricted. (bookdepository.com)
- might lead to the discovery of completely novel antibiotic scaffolds" and suggest that "considering YbeY's high level of conservation, its essential nature in many pathogens, and its ability to sensitize pathogens by disrupting stress tolerance and virulence, a YbeY-specific antibiotic could have broad-spectrum antimicrobial activity. (redorbit.com)
- All of these offer ultimate explanations for virulence in pathogens. (wikipedia.org)
- In vivo infections of rice demonstrate that M. oryzae virulence is enhanced, quite paradoxically, when a public good mutant is present in a population of high-virulence pathogens. (org.in)
- Drug-resistant microorganisms with a higher fitness - can medicines boost pathogens? (springer.com)
- Recent studies indicate that mitochondrial functions impinge on cell wall integrity, drug tolerance, and virulence of human fungal pathogens. (asm.org)
- Many intracellular eukaryotic pathogens use the secretory system for the expression of virulence factors that are crucial for pathogenesis, including adhesion, motility, host cell invasion or the co-opting of host cellular processes , . (prolekare.cz)
- My lab is focused on understanding the survival and virulence strategies employed by a group of important bacterial pathogens collectively known as E xtraintestinal P athogenic E scherichia c oli , or ExPEC. (utah.edu)
- Then, the 20th-century emergence of commensal microbes that were previously considered to be avirulent, such as Candida albicans ( 7 ) and Staphylococcus epidermidis ( 40 ), as clinically relevant pathogens provided clear evidence that virulence can be a function of the immune status of the host. (asm.org)
- Given that the outcome of microbial infection is often a function of the immune status of the host and that a susceptible host is required for microbial virulence, it makes sense to categorize microbial pathogens based on how they are acquired. (asm.org)
- Vartika Srivastava, Rajeev Kumar Singla and Ashok Kumar Dubey*, "Emerging Virulence, Drug Resistance and Future Anti-fungal Drugs for Candida Pathogens", Current Topics in Medicinal Chemistry (2018) 18: 759. (eurekaselect.com)
Evolution of virulence1
- Thus, control of the innate host response and IFN actions is a key feature of WNV pathogenesis and replication fitness. (asm.org)
- We found that a Δ ireA mutant was avirulent in a mouse model of invasive aspergillosis, which contrasts the partial virulence of a Δ hacA mutant, suggesting that IreA contributes to pathogenesis independently of HacA. (prolekare.cz)
- The results indicate that MgAtr4 is a virulence factor of M. graminicola during pathogenesis on wheat and may function in protection against fungitoxic compounds present around the substomatal cavities of wheat leaves. (apsnet.org)
- Although our comprehension of the epidemiology, pathogenesis, and virulence factors of S. pneumoniae has improved in recent years, the basis for whether colonization with a specific strain establishes asymptomatic colonization or produces local or invasive diseases requires further elucidation. (pubmedcentralcanada.ca)
- The present study provides a robust phylogenetic foundation for the study of these important virulence-associated phenotypes in P. syringae host colonization and pathogenesis. (asm.org)
- Although all of these toxins have been shown to modulate virulence, none are essential for the disease process ( 5 ), and there is still no consensus on their overall importance in pathogenesis ( 14 ). (asm.org)
- 3. Determining how ExPEC-associated toxins and other virulence factors modulate and hijack host signaling events, including host cell death, survival, and inflammatory pathways. (utah.edu)
- This view, which regards virulence as a microbial characteristic, is supported by the observation that certain microbes require specific factors, such as toxins and capsules, for animal virulence. (asm.org)
- Multi-trait cooperative interactions are widespread, so we caution against the indiscriminant application of anti-virulence therapy as a disease-management strategy. (org.in)
- In terms of recent advancement, quorum sensing disruption is one of the emerging anti-virulence strategies against bacterial infections [ 5 ]. (mdpi.com)
- An anti-virulence approach is relevant in the current context, as antibiotics are losing their efficacy, and many bacteria are becoming multi-drug resistant (MDR) [ 6 ]. (mdpi.com)
- Antifungal activity, anti-virulence agents, Candida spp. (eurekaselect.com)
Explored the relationship between virulence1
- Consistent with this finding, the virulence of MAD78 was unmasked upon infection of mice lacking IFNAR. (asm.org)
- This suggests that aggregating improves R. solanacearum survival in soil and facilitates infection and that it reduces pathogenic fitness later in disease. (asm.org)
- We found that infection by siderophore-producing bacteria (cooperators) results in more rapid host death than does infection by non-producers (cheats), and that mixtures of both result in intermediate levels of virulence. (biomedcentral.com)
- The virulence of these isolates was compared in rodent models of necrotizing pneumonia and skin infection. (asm.org)
- We conclude that ACME is not necessary for virulence in rodent models of CA-MRSA USA300 pneumonia or skin infection. (asm.org)
- This makes C. elegans a relevant model for determining the infectivity and fitness of antibiotic-resistant bacteria during a host infection. (asm.org)
- In the present work, novel allelic efpR variants were isolated from populations propagated on other plant species, thus suggesting that mutations in efpR were not solely associated to a fitness gain on bean, but also on additional hosts. (nih.gov)
- Mutations that evade immunity but maintain viral fitness and virulence, such as the N489K mutation, are emerging. (cdc.gov)
- Further analysis showed that the acquired mutations impaired viral fitness and virulence, rather than making the virus more virulent. (eurekalert.org)
- In this study, we estimated the rate and mean effect of spontaneous mutations that affect fitness in a mutator strain of Escherichia coli and review some of the estimation methods associated with mutation accumulation (MA) experiments. (royalsocietypublishing.org)
- From the decline in mean fitness and the increase in variance between lines, we estimated a minimum mutation rate to deleterious mutations of 0.005 (±0.001 with 95% confidence) and a maximum mean fitness effect per deleterious mutation of 0.03 (±0.01 with 95% confidence). (royalsocietypublishing.org)
- By definition, parasites cause harm to their hosts (i.e., they cause virulence), but explaining why they do so remains a challenge for evolutionary biologists. (pnas.org)
- The most popular evolutionary explanation asserts that virulence is an unavoidable consequence of selection to maximize parasite fitness ( 9 ⇓ ⇓ ⇓ ⇓ ⇓ ⇓ ⇓ - 17 ). (pnas.org)
- According to evolutionary medicine , virulence increases with horizontal transmission (between non-relatives) and decreases with vertical transmission (from parent to child). (wikipedia.org)
Change in virulence1
Contribute to virulence3
- Pathogenic species of the bacterial genus Mycobacterium , including M. tuberculosis , carry these integrated viral genomes (prophage) that are hypothesized to contribute to virulence. (maineidea.net)
- The majority of pathogenic bacteria, including M. tuberculosis , carry viral genomes (prophage) within the bacterial genome that are thought to contribute to virulence. (maineidea.net)
- Determining how prophage within non-tuberculosis pathogenic mycobacteria contribute to virulence will provide opportunities to develop and improve treatment of bacterial diseases. (maineidea.net)
Interference with virulence1
- Impact of AmpC Derepression on Fitness and Virulence: the Mechanism or the Pathway? (asm.org)
- The mechanism was bacteriostatic and interfered with replication mediated by the virulence-associated SPI2 type III secretion system. (asm.org)
- These results imply that omeprazole can be used to block the virulence factor-mediated intracellular replication of S . Typhimurium, and that its mechanism of growth inhibition is different from that mediated by bafilomycin A 1 . (asm.org)
- Any movement on the virulence axis, towards higher or lower virulence, will result in lower fitness for the parasite, and thus will be selected against. (wikipedia.org)
- Under these conditions, mixed-strain infections are predicted to show lower virulence (host mortality) than are single-clone infections, due to competition favouring non-contributing social 'cheats' whose presence will reduce within-host growth. (biomedcentral.com)
- This idea has led researchers to predict how human interventions-such as vaccines-may alter virulence evolution, yet empirical support is critically lacking. (pnas.org)
- The demonstration that animal and/or in vitro passage can alter virulence illustrated that virulence is not necessarily a stable or invariant trait. (asm.org)
- We studied a protozoan parasite of monarch butterflies and found that higher levels of within-host replication resulted in both higher virulence and greater transmission, thus lending support to the idea that selection for parasite transmission can favor parasite genotypes that cause substantial harm. (pnas.org)
- However, the host, being the parasite's resource and habitat in a way, suffers from this higher virulence . (wikipedia.org)
- Numerous models of parasite evolution predict that mixed infections have higher virulence (host mortality rate) than do single-genotype infections. (biomedcentral.com)
- Both in vitro and in vivo defect in the growth rate was found in the JPAB02 strain in competition with the ATCC 17978 wt, highlighting the effect of Omp33 on the metabolic fitness. (nih.gov)
- A complex that catalyzes the membrane integration of β barrel proteins and a molecular chaperone promote the complete assembly of a bacterial virulence factor in vitro. (elifesciences.org)
- N439K variant SARS-CoV-2 structural dynamics, phylogeny, fitness, and virulence were assessed with in silico and in vitro experiments and an observational study. (cdc.gov)
- In vitro growth experiments in different media showed no fitness penalty associated with the disruption of MgAtr4 . (apsnet.org)
- To verify the association between plasmids and fitness, growth kinetics of the transconjugants were performed. (frontiersin.org)
- The nucleotide sequence of pRS218 showed a 41- 46% similarity to other neonatal meningitis-causing E. coli (NMEC) plasmids and remarkable nucleotide sequence similarity (up to 100%) to large virulence plasmids of E. coli associated with acute cystitis. (nih.gov)
- The horizontal acquisition of virulence plasmids is potentiated by production practices in plant nurseries and is sufficient to transition Rhodococcus from being beneficial to being pathogenic. (elifesciences.org)
- A separate experiment confirmed genetic relationships between parasite replication and virulence, and showed that parasite genotypes from two monarch populations caused different virulence. (pnas.org)
- There were also indications of fitness costs of the virulence in both populations. (wur.nl)
- Understanding why parasite virulence seldom escalates similarly in natural populations could help us to manage virulence and deal with emerging diseases. (sciencemag.org)
- both viral fitness and virulence is substantially higher in familiar versus unfamiliar MHC genotypes. (pnas.org)
- Practical applications of viral fitness in clinical practice. (springer.com)
- Geretti AM. The clinical significance of viral fitness. (springer.com)
- The mutation increases spike affinity for ACE2 receptors while viral fitness and virulence are unchanged from wild-type SARS-CoV-2. (cdc.gov)
- Temporary reduction and long-term loss of virulence were found. (wur.nl)
- This reduction in virulence was independent of the wheat cultivar used. (apsnet.org)
- Reduction of Culiseta melanura fitness by eastern equine encephalomyelitis virus. (ajtmh.org)
- A rapid increase of parasite-induced reduction of host fitness is the most general result of SPEs ( Tables 1 and 2 and Fig. 1 ) and it sometimes happens within only three passages ( 4-6 ). (sciencemag.org)
- Theory predicts that parasites could evolve virulence (i.e., parasite-induced reductions in host fitness) by balancing the transmission benefits of parasite replication with the costs of host death. (pnas.org)
- One definition of virulence is the host's parasite-induced loss of fitness . (wikipedia.org)
- in most cases discussed in this review, virulence refers to parasite-induced host mortality. (royalsocietypublishing.org)
- In an ecological context, virulence can be defined as the host's parasite-induced loss of fitness. (wikipedia.org)
- He came to the conclusion that virulence tends to remain especially high in waterborne and vector-borne infections, such as cholera and Dengue . (wikipedia.org)
- These data demonstrate that mixed clone infections can favour the evolution of social cheats, and thus decrease virulence when parasite growth is dependent on cooperative behaviours. (biomedcentral.com)
- Of particular interest is the extent to which cooperative behaviour [ 8 , 9 ] will influence the virulence of mixed infections. (biomedcentral.com)
- The parasite's fitness is determined by its success in transmitting offspring to other hosts. (wikipedia.org)
- This might induce faster host death, and act against the parasite's fitness by reducing probability to encounter another host (killing the host too fast to allow for transmission). (wikipedia.org)
- The idea is, then, that there exists an equilibrium point of virulence, where parasite's fitness is highest. (wikipedia.org)
- Within-host competition generally drives an increase in a parasite's virulence in a new host, whereas the parasite becomes avirulent to its former host, indicating a trade-off between parasite fitnesses on different hosts. (sciencemag.org)
- Parasites thus face a trade-off between the benefits of increased replication (i.e., increased transmission rate) and the costs (i.e., virulence or immune clearance), resulting in highest fitness at intermediate levels of parasite replication. (pnas.org)
- A small number of studies have shown positive relationships between within-host replication and virulence ( 21 ) and between virulence and parasite transmission potential ( 22 ⇓ - 24 ), or have shown optimal transmission at an intermediate level of virulence ( 25 ). (pnas.org)
- However, no studies have simultaneously quantified the relationships between within-host parasite replication, virulence, and transmission to examine support for a maximum attainable parasite fitness owing to a trade-off between the costs and benefits of parasite replication. (pnas.org)
- Deletion of a homologous opp in S. pyogenes impaired virulence and alters the regulation of virulence factor expression ( 20 ). (asm.org)
- In addition, full or partial virulence could be restored to the Δ ireA mutant by complementation with either the induced form of the hacA mRNA, hacA i , or an ireA deletion mutant that was incapable of processing the hacA mRNA, ireA Δ10 . (prolekare.cz)