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.Virulence Factors: Those components of an organism that determine its capacity to cause disease but are not required for its viability per se. Two classes have been characterized: TOXINS, BIOLOGICAL and surface adhesion molecules that effect the ability of the microorganism to invade and colonize a host. (From Davis et al., Microbiology, 4th ed. p486)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.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.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.Genes, Bacterial: The functional hereditary units of BACTERIA.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.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.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.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.Escherichia coli Infections: Infections with bacteria of the species ESCHERICHIA COLI.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.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.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-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.Bacterial Outer Membrane Proteins: Proteins isolated from the outer membrane of Gram-negative bacteria.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".DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.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.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.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.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.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.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Plant Diseases: Diseases of plants.Vibrio cholerae: The etiologic agent of CHOLERA.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.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).Yersinia pestis: The etiologic agent of PLAGUE in man, rats, ground squirrels, and other rodents.Streptolysins: Exotoxins produced by certain strains of streptococci, particularly those of group A (STREPTOCOCCUS PYOGENES), that cause HEMOLYSIS.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Cryptococcus neoformans: A species of the fungus CRYPTOCOCCUS. Its teleomorph is Filobasidiella neoformans.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.Streptococcal Infections: Infections with bacteria of the genus STREPTOCOCCUS.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.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.Mice, Inbred BALB CPyocyanine: Antibiotic pigment produced by Pseudomonas aeruginosa.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.Fimbriae Proteins: Proteins that are structural components of bacterial fimbriae (FIMBRIAE, BACTERIAL) or sex pili (PILI, SEX).Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Salmonella typhimurium: A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.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.Genetic 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.Exotoxins: Toxins produced, especially by bacterial or fungal cells, and released into the culture medium or environment.Serotyping: Process of determining and distinguishing species of bacteria or viruses based on antigens they share.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.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.Candida albicans: A unicellular budding fungus which is the principal pathogenic species causing CANDIDIASIS (moniliasis).Lethal Dose 50: The dose amount of poisonous or toxic substance or dose of ionizing radiation required to kill 50% of the tested population.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 pseudotuberculosis: A human and animal pathogen causing mesenteric lymphadenitis, diarrhea, and bacteremia.Pseudomonas Infections: Infections with bacteria of the genus PSEUDOMONAS.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.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.Yersinia enterocolitica: A species of the genus YERSINIA, isolated from both man and animal. It is a frequent cause of bacterial gastroenteritis in children.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.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.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.Hemolysis: The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.Microbial Viability: Ability of a microbe to survive under given conditions. This can also be related to a colony's ability to replicate.Porphyromonas gingivalis: A species of gram-negative, anaerobic, rod-shaped bacteria originally classified within the BACTEROIDES genus. This bacterium produces a cell-bound, oxygen-sensitive collagenase and is isolated from the human mouth.Staphylococcal Infections: Infections with bacteria of the genus STAPHYLOCOCCUS.Biofilms: Encrustations, formed from microbes (bacteria, algae, fungi, plankton, or protozoa) embedding in extracellular polymers, that adhere to surfaces such as teeth (DENTAL DEPOSITS); PROSTHESES AND IMPLANTS; and catheters. Biofilms are prevented from forming by treating surfaces with DENTIFRICES; DISINFECTANTS; ANTI-INFECTIVE AGENTS; and antifouling agents.Vibrio Infections: Infections with bacteria of the genus VIBRIO.Fungal Proteins: Proteins found in any species of fungus.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Bordetella pertussis: A species of gram-negative, aerobic bacteria that is the causative agent of WHOOPING COUGH. Its cells are minute coccobacilli that are surrounded by a slime sheath.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.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.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.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.)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.Bacillus anthracis: A species of bacteria that causes ANTHRAX in humans and animals.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.Helicobacter pylori: A spiral bacterium active as a human gastric pathogen. It is a gram-negative, urease-positive, curved or slightly spiral organism initially isolated in 1982 from patients with lesions of gastritis or peptic ulcers in Western Australia. Helicobacter pylori was originally classified in the genus CAMPYLOBACTER, but RNA sequencing, cellular fatty acid profiles, growth patterns, and other taxonomic characteristics indicate that the micro-organism should be included in the genus HELICOBACTER. It has been officially transferred to Helicobacter gen. nov. (see Int J Syst Bacteriol 1989 Oct;39(4):297-405).Shigella flexneri: A bacterium which is one of the etiologic agents of bacillary dysentery (DYSENTERY, BACILLARY) and sometimes of infantile gastroenteritis.Yersinia Infections: Infections with bacteria of the genus YERSINIA.Siderophores: Low-molecular-weight compounds produced by microorganisms that aid in the transport and sequestration of ferric iron. (The Encyclopedia of Molecular Biology, 1994)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.Yersinia: A genus of gram-negative, facultatively anaerobic rod- to coccobacillus-shaped bacteria that occurs in a broad spectrum of habitats.Yersinia pseudotuberculosis Infections: Infections with bacteria of the species YERSINIA PSEUDOTUBERCULOSIS.Cryptococcosis: Infection with a fungus of the species CRYPTOCOCCUS NEOFORMANS.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.Polysaccharides, Bacterial: Polysaccharides found in bacteria and in capsules thereof.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.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.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.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.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.Enterotoxins: Substances that are toxic to the intestinal tract causing vomiting, diarrhea, etc.; most common enterotoxins are produced by bacteria.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.Hyphae: Microscopic threadlike filaments in FUNGI that are filled with a layer of protoplasm. Collectively, the hyphae make up the MYCELIUM.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.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.Virulence Factors, Bordetella: A set of BACTERIAL ADHESINS and TOXINS, BIOLOGICAL produced by BORDETELLA organisms that determine the pathogenesis of BORDETELLA INFECTIONS, such as WHOOPING COUGH. They include filamentous hemagglutinin; FIMBRIAE PROTEINS; pertactin; PERTUSSIS TOXIN; ADENYLATE CYCLASE TOXIN; dermonecrotic toxin; tracheal cytotoxin; Bordetella LIPOPOLYSACCHARIDES; and tracheal colonization factor.Enterococcus faecalis: A species of gram-positive, coccoid bacteria commonly isolated from clinical specimens and the human intestinal tract. Most strains are nonhemolytic.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.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.Salmonella Infections, Animal: Infections in animals with bacteria of the genus SALMONELLA.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.Diarrhea: An increased liquidity or decreased consistency of FECES, such as running stool. Fecal consistency is related to the ratio of water-holding capacity of insoluble solids to total water, rather than the amount of water present. Diarrhea is not hyperdefecation or increased fecal weight.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.Proteus mirabilis: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that is frequently isolated from clinical specimens. Its most common site of infection is the urinary tract.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.Adhesins, Escherichia coli: Thin, filamentous protein structures, including proteinaceous capsular antigens (fimbrial antigens), that mediate adhesion of E. coli to surfaces and play a role in pathogenesis. They have a high affinity for various epithelial cells.Trans-Activators: Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.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.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Epithelial Cells: Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.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.Streptococcus suis: A species of STREPTOCOCCUS isolated from pigs. It is a pathogen of swine but rarely occurs in humans.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.Phagocytosis: The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).HomoserineAeromonas 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.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)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).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.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Bacterial Vaccines: Suspensions of attenuated or killed bacteria administered for the prevention or treatment of infectious bacterial disease.Genetic Variation: Genotypic differences observed among individuals in a population.Peptide Hydrolases: Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.Myxoma virus: The type species of LEPORIPOXVIRUS causing infectious myxomatosis, a severe generalized disease, in rabbits. Tumors are not always present.Cysteine Endopeptidases: ENDOPEPTIDASES which have a cysteine involved in the catalytic process. This group of enzymes is inactivated by CYSTEINE PROTEINASE INHIBITORS such as CYSTATINS and SULFHYDRYL REAGENTS.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.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Mutagenesis: Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.Shiga Toxin 2: A toxin produced by certain pathogenic strains of ESCHERICHIA COLI such as ESCHERICHIA COLI O157. It shares 50-60% homology with SHIGA TOXIN and SHIGA TOXIN 1.Shiga Toxin: A toxin produced by SHIGELLA DYSENTERIAE. It is the prototype of class of toxins that inhibit protein synthesis by blocking the interaction of ribosomal RNA; (RNA, RIBOSOMAL) with PEPTIDE ELONGATION FACTORS.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.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).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.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)Xanthomonas: A genus in the family XANTHOMONADACEAE whose cells produce a yellow pigment (Gr. xanthos - yellow). It is pathogenic to plants.Francisella tularensis: The etiologic agent of TULAREMIA in man and other warm-blooded animals.Gene Expression Regulation, Fungal: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in fungi.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.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.Staphylococcal Protein A: A protein present in the cell wall of most Staphylococcus aureus strains. The protein selectively binds to the Fc region of human normal and myeloma-derived IMMUNOGLOBULIN G. It elicits antibody activity and may cause hypersensitivity reactions due to histamine release; has also been used as cell surface antigen marker and in the clinical assessment of B lymphocyte function.O Antigens: The lipopolysaccharide-protein somatic antigens, usually from gram-negative bacteria, important in the serological classification of enteric bacilli. The O-specific chains determine the specificity of the O antigens of a given serotype. O antigens are the immunodominant part of the lipopolysaccharide molecule in the intact bacterial cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Aeromonas: A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs singly, in pairs, or in short chains. Its organisms are found in fresh water and sewage and are pathogenic to humans, frogs, and fish.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.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).Gram-Negative Bacterial Infections: Infections caused by bacteria that show up as pink (negative) when treated by the gram-staining method.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).Immune Evasion: Methods used by pathogenic organisms to evade a host's immune system.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.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.Bacteroidaceae Infections: Infections with bacteria of the family BACTEROIDACEAE.Streptococcus agalactiae: A bacterium which causes mastitis in cattle and occasionally in man.Myxomatosis, InfectiousMembrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.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)Sigma Factor: A protein which is a subunit of RNA polymerase. It effects initiation of specific RNA chains from DNA.Pectobacterium carotovorum: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that causes rotting, particularly of storage tissues, of a wide variety of plants and causes a vascular disease in CARROTS; and POTATO plants.Melanins: Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration.Pyelonephritis: Inflammation of the KIDNEY involving the renal parenchyma (the NEPHRONS); KIDNEY PELVIS; and KIDNEY CALICES. It is characterized by ABDOMINAL PAIN; FEVER; NAUSEA; VOMITING; and occasionally DIARRHEA.Bordetella: A genus of gram-negative, aerobic bacteria whose cells are minute coccobacilli. It consists of both parasitic and pathogenic species.Helicobacter Infections: Infections with organisms of the genus HELICOBACTER, particularly, in humans, HELICOBACTER PYLORI. The clinical manifestations are focused in the stomach, usually the gastric mucosa and antrum, and the upper duodenum. This infection plays a major role in the pathogenesis of type B gastritis and peptic ulcer disease.Edwardsiella tarda: A species of EDWARDSIELLA distinguished by its hydrogen sulfide production. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Lycopersicon esculentum: A plant species of the family SOLANACEAE, native of South America, widely cultivated for their edible, fleshy, usually red fruit.Vibrio parahaemolyticus: A species of bacteria found in the marine environment, sea foods, and the feces of patients with acute enteritis.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Cholera Toxin: An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells, and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.Electrophoresis, Gel, Pulsed-Field: Gel electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.Listeriosis: Infections with bacteria of the genus LISTERIA.ADP Ribose Transferases: Enzymes that transfer the ADP-RIBOSE group of NAD or NADP to proteins or other small molecules. Transfer of ADP-ribose to water (i.e., hydrolysis) is catalyzed by the NADASES. The mono(ADP-ribose)transferases transfer a single ADP-ribose. POLY(ADP-RIBOSE) POLYMERASES transfer multiple units of ADP-ribose to protein targets, building POLY ADENOSINE DIPHOSPHATE RIBOSE in linear or branched chains.Anthrax: An acute infection caused by the spore-forming bacteria BACILLUS ANTHRACIS. It commonly affects hoofed animals such as sheep and goats. Infection in humans often involves the skin (cutaneous anthrax), the lungs (inhalation anthrax), or the gastrointestinal tract. Anthrax is not contagious and can be treated with antibiotics.Mice, Inbred C57BLHemagglutination: The aggregation of ERYTHROCYTES by AGGLUTININS, including antibodies, lectins, and viral proteins (HEMAGGLUTINATION, VIRAL).Urease: An enzyme that catalyzes the conversion of urea and water to carbon dioxide and ammonia. EC 3.5.1.5.Bacteremia: The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion.Streptococcus mutans: A polysaccharide-producing species of STREPTOCOCCUS isolated from human dental plaque.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Bacterial Load: Measurable quantity of bacteria in an object, organism, or organism compartment.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Acyl-Butyrolactones: Cyclic esters of acylated BUTYRIC ACID containing four carbons in the ring.Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.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.Aspergillus fumigatus: A species of imperfect fungi from which the antibiotic fumigatin is obtained. Its spores may cause respiratory infection in birds and mammals.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.Brucella suis: A species of gram-negative bacteria, primarily infecting SWINE, but it can also infect humans, DOGS, and HARES.Xanthomonas campestris: A species of gram-negative, aerobic bacteria that is pathogenic for plants.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).Salmonella Infections: Infections with bacteria of the genus SALMONELLA.Shiga-Toxigenic Escherichia coli: Strains of ESCHERICHIA COLI with the ability to produce at least one or more of at least two antigenically distinct, usually bacteriophage-mediated cytotoxins: SHIGA TOXIN 1 and SHIGA TOXIN 2. These bacteria can cause severe disease in humans including bloody DIARRHEA and HEMOLYTIC UREMIC SYNDROME.Sequence Deletion: Deletion of sequences of nucleic acids from the genetic material of an individual.Streptococcus: A genus of gram-positive, coccoid bacteria whose organisms occur in pairs or chains. No endospores are produced. Many species exist as commensals or parasites on man or animals with some being highly pathogenic. A few species are saprophytes and occur in the natural environment.Artificial Gene Fusion: The in vitro fusion of GENES by RECOMBINANT DNA techniques to analyze protein behavior or GENE EXPRESSION REGULATION, or to merge protein functions for specific medical or industrial uses.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Repressor Proteins: Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.

*  Solved] Antibiotic-resistance genes, as well as other virulence factor genes, are | SolutionInn

... as well as other virulence factor genes, are easily passed between bacterial cells through horizontal gene transfer. a. Conduct ... Antibiotic-resistance genes, as well as other virulence factor genes, are easily passed between bacterial cells through ...
solutioninn.com/antibioticresistance-genes-as-well-as-other-virulence-factor-genes-are

*  'virulence factors' Protocols and Video...

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking', 'A Murine Model of Group B ... Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent ... Applying an Inducible Expression System to Study Interference of Bacterial Virulence Factors with Intracellular Signaling', 'A ... The Madagascar Hissing Cockroach As an Alternative Non-Mammalian Animal Model to Investigate Virulence, Pathogenesis, and Drug ...
https://jove.com/keyword/virulence factors

*  2-for-1 bacterial virulence factor revealed | EurekAlert! Science News

Drugs that hobble the production of virulence factors, small molecules that help bacteria to establish an infection in a host, ... In Infectious Diseases he describes recent work on a target virulence factor. ... One class of virulence factors common to many pathogens is siderophores, small molecules whose job is to seek out iron in the ... Virulence factors allow bacteria to evade the human immune system, to infect tissues and cells and to establish a foothold ...
https://eurekalert.org/pub_releases/2016-01/wuis-tbv011516.php

*  Entamoeba histolytica. Phagocytosis as a virulence factor. | JEM

Phagocytosis as a virulence factor.. E Orozco, G Guarneros, A Martinez-Palomo, T Sánchez ... The virulence of clone L-6 and strain HM1:IMSS was measured. The inoculum required to induce liver abscesses in 50% of the ... Virulence revertants were obtained by successive passage of L-6 trophozoites through the liver of young hamsters. The ... In this paper, we attempted to define the role of phagocytosis in the virulence of Entamoeba histolytica. We have isolated, ...
jem.rupress.org/content/158/5/1511

*  The RNA-binding protein CsrA plays a central role in positively regulating virulence factors in Erwinia amylovora | Scientific...

Alternative sigma factor RpoN and its modulator protein YhbH are indispensable for Erwinia amylovora virulence. . Mol. Plant ... The RNA-binding protein CsrA plays a central role in positively regulating virulence factors in Erwinia amylovora. Sci. Rep. 6 ... The RNA-binding protein CsrA plays a central role in positively regulating virulence factors in Erwinia amylovora. *Veronica ... The RNA-binding protein CsrA plays a central role in positively regulating virulence factors in Erwinia amylovora. *Download as ...
nature.com/articles/srep37195?error=cookies_not_supported&code=1288fd7f-9787-4eef-a86d-ccea6ff198e1

*  African Journal of Microbiology Research - discriminative multiplex (hexaplex) pcr strategy for the detection of methicillin...

... and occurrence of virulence factors. It targets the nuc (Specific forS. aureus), mec A (methicillin resistance determinant), ... fem A and fem B (S. aureusspecific factors essential for methicillin resistance), Luk S/F PV (encodes for Panton Valentine ... allow more accurate and quick way out for identification of Staphylococcus aureus along with its virulence capabilities. This ... 2013). Discriminative multiplex (hexaplex) PCR strategy for the detection of methicillin resistance and virulence factors in ...
academicjournals.org/journal/AJMR/article-abstract/316E43B17592

*  Investigation of Haemophilus somnus Virulence Factors: Lipooligosaccharide Sialylation and Inhibition of Superoxide Anion...

One of the reported virulence factors that H. somnus may use to persist in the host is resistance to intracellular killing. It ... Investigation of Haemophilus somnus Virulence Factors: Lipooligosaccharide Sialylation and Inhibition of Superoxide Anion ...
https://vtechworks.lib.vt.edu/handle/10919/26848

*  Dissemination of Virulence Factors and Antimicrobial Resistance in Faecal Enterococci from Poultry | BenthamScience

Dissemination of Virulence Factors and Antimicrobial Resistance in Faecal Enterococci from Poultry. Author(s): Andrea Brtkova, ... No relationship between virulence factors and resistance to antimicrobials was found. The data of this study proved relatively ... No relationship between virulence factors and resistance to antimicrobials was found. The data of this study proved relatively ... Dissemination of Virulence Factors and Antimicrobial Resistance in Faecal Enterococci from Poultry. ...
eurekaselect.com/88090

*  E. coli: Diseases Caused in Presence of Virulence Factors | Internal Medicine Board Exam Recertification | Knowmedge

Diseases Caused in Presence of Virulence Factors - Microbiology Mnemonics - Knowmedge is an Internal Medicine Qbank alternative ...
knowmedge.com/medical_mnemonics/Microbiology_mnemonics/E.-coli:-Diseases-Caused-in-Presence-of-Virulence-Factors/998

*  Microbiology Society Journals | Iron deficiency leads to inhibition of oxygen transfer and enhanced formation of virulence...

The formation of the virulence factor elastase and the iron chelators pyoverdine and pyochelin also significantly increased ... f Iron deficiency leads to inhibition of oxygen transfer and enhanced formation of virulence factors in cultures of Pseudomonas ... Iron deficiency leads to inhibition of oxygen transfer and enhanced formation of virulence factors in cultures of Pseudomonas ... The formation of the virulence factor elastase and the iron chelators pyoverdine and pyochelin also significantly increased ...
mic.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.26276-0

*  "Stringent Response Regulation of Virulence Factors in Vibrio Cholera" by David Raskin, Arunima Mishra et al.

Stringent response activated gene expression of virulence factors (those encoding CT and TCP) and some ToxR regulon components ... and diarrheal symptoms are primarily produced by the virulence factor cholera toxin (CT). CT and TCP expression is regulated by ... Components of the ToxR regulon include ToxT, a transcription factor that directly initiates transcription of the CT and TCP ... Upstream regulators include the integral membrane proteins TcpP and ToxR, transcription factors necessary for expression of ...
mushare.marian.edu/mucom_rd/20/

*  British Library EThOS: Host factors affecting the virulence of Campylobacter

The integrity of the intestinal epithelium is maintained by intercellular junctions, such as tight junctions. These are crucial in creating a barrier against the intestinal environment. Studies have shown that pathogenic bacteria can disrupt the structure of tight junction proteins to facilitate their paracellular passage into the underlying tissues. It is known that colonisation of the intestinal epithelium by Campylobacter affects intestinal integrity by disrupting occludin, an integral tight junction protein, enhancing the paracellular passage or Campylobacter. In response to the influx of foreign antigens, the host will mount an immune response elevating the levels of proinflammatory cytokines, such as TNF-a and IFN-y. Such cytokines have been shown to affect the structure of tight junctions during intestinal inflammation disrupting barrier function and facilitating the passage of luminal antigens into the underlying tissues. Published data show that some bacteria are capable of elevating ...
ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557965

*  Structural mimicry for vinculin activation by IpaA, a virulence factor of Shigella flexneri | EMBO Reports

Structural mimicry for vinculin activation by IpaA, a virulence factor of Shigella flexneri. Cyril Hamiaux, André van Eerde, ... Stebbins CE, Galán JE (2001) Structural mimicry in bacterial virulence. Nature 412: 701-705. ... The close similarities between the binding modes of the bacterial virulence protein IpaA to VD1 and of the endogenous ... Induction of membrane ruffles on epithelial cells depends on a virulence plasmid‐encoded type III secretion (TTS) system ( ...
embor.embopress.org/content/7/8/794.full

*  "Prevalence of Virulence Factors Among Hemolytic Escherichia coli" by Harley W. Moon, Nancy A. Cornick et al.

Moon, Harley W.; Cornick, Nancy A.; Hoffman, Lorraine J.; and Bosworth, Brad T., "Prevalence of Virulence Factors Among ...
lib.dr.iastate.edu/swinereports_1997/41/

*  Heparanase is a Host-Encoded Virulence Factor for Herpes Simplex Virus Ocular Infection | IOVS | ARVO Journals

Our study demonstrates a novel role for heparanse as a host encoded virulence factor that directly controls the emergence of ... Conclusions : Overall, our findings implicate heparanse as a novel cellular regulator and a virulence factor for corneal ... Deepak Shukla, Alex Agelidis, Satvik Hadigal; Heparanase is a Host-Encoded Virulence Factor for Herpes Simplex Virus Ocular ... Heparanase is a Host-Encoded Virulence Factor for Herpes Simplex Virus Ocular Infection ...
iovs.arvojournals.org/article.aspx?articleid=2562556

*  Effects of Long-Term, Low-Dose Macrolide Treatment on Pseudomonas aeruginosa PAO1 Virulence Factors In Vitro

Low-Dose Macrolide Treatment on Pseudomonas aeruginosa PAO1 Virulence Factors In Vitro, Shusaku S, Yoko M, Katsumi F, ... inhibits multiple virulence factors in a time-dependent fashion. Those virulence factors are controlled by regulatory ... Figure 4: Virulence factors such as total protease (A), elastase (B), and pyocyanin (C) of PAO1 exposed to erythromycin (â  ... Correlation of virulence factors with macrolide. Although long-term, low-dose macrolide treatment did not alter the P. ...
acmicrob.com/microbiology/effects-of-longterm-lowdose-macrolidetreatment-on-pseudomonas-aeruginosapao1-virulence-factors-in-vitro.php?aid=19781

*  Chlamydia trachomatis In Vivo to In Vitro Transition Reveals Mechanisms of Phase Variation and Down-Regulation of Virulence...

Chlamydia trachomatis In Vivo to In Vitro Transition Reveals Mechanisms of Phase Variation and Down-Regulation of Virulence ... Factors. . Download books free in pdf. Online library with books, university works and thousands of documents available to read ... RNA-sequencing analyses revealed that a deletion event involving CT135 impacted the expression of multiple virulence factors, ... This reflects a scenario of attenuation of C. trachomatis virulence in vitro, which may take place independently or in a ...
books.duhnnae.com/2017/jun9/149845217549-Chlamydia-trachomatis-In-Vivo-to-In-Vitro-Transition-Reveals-Mechanisms-of-Phase-Variation-and-Down-Regulation-of-Virulence-Factors.php

*  The virulence factor LecB varies in clinical isolates: consequences for ligand binding and drug discovery - Helmholtz Zentrum...

The virulence factor LecB varies in clinical isolates: consequences for ligand binding and drug discovery 2016 Chem. Sci.. en. ... The virulence factor LecB varies in clinical isolates: consequences for ligand binding and drug discovery. Authors:. Sommer, ... The virulence factor LecB varies in clinical isolates: consequences for ligand binding and drug discovery 2016 Chem. Sci.. ... The virulence factor LecB varies in clinical isolates: consequences for ligand binding and drug discovery. en. ...
hzi.openrepository.com/hzi/handle/10033/611223

*  Molecular Detection of virulence factor genes in pseudomonas aeruginosa isolated from human and animals in Diwaniya province |...

Molecular Detection of virulence factor genes in pseudomonas aeruginosa isolated from human and animals in Diwaniya province ... these virulence factors encoding by virulence genes located in the chromosome of Pseudomonas aeruginosa. However, this study ... Molecular Detection of virulence factor genes in pseudomonas aeruginosa isolated from human and animals in Diwaniya province. ... Virulent factors are molecules that produced by pathogenic Pseudomonas aeruginosa that enable it to play a great role in causes ...
journals.uokufa.edu.iq/index.php/kjvs/article/view/6010

*  Bacterial adhesin - Wikipedia

a b c d Identified Virulence Factors of UPEC : Adherence, State Key Laboratory for Moleclular Virology and Genetic Engineering ... Adhesins as Virulence Factors[edit]. The majority of bacterial pathogens exploit specific adhesion to host cells as their main ... Adhesins are a type of virulence factor.. Adherence is an essential step in bacterial pathogenesis or infection, required for ... This prevalence marks them as key microbial virulence factors in addition to a bacterium's ability to produce toxins and resist ...
https://en.wikipedia.org/wiki/Adhesin

*  Characteristics of Streptococcus Pyogenes | LIVESTRONG.COM

Virulence Factors. Streptococcus pyogenes produces numerous virulence factors that lend to its pathogenicity, or disease- ...
livestrong.com/article/82105-characteristics-streptococcus-pyogenes/

*  KAKEN - Research Projects | Viral and host factors contributing to the neuro-virulence of rabies virus. (KAKENHI-PROJECT...

Viral and host factors contributing to the neuro-virulence of rabies virus.. Research Project ... Each passaged virus failed to regain lethal virulence for adult mice, although the viruses were increased to level of mouse ... These changed positions of a nucleotide and two amino acids may necessary for mouse virulence.. 3) A comparative analysis of ... 2) The revertant strain acquired partially virulence had each one amino acid substitution in G and M proteins. and one ...
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08456150/

*  Gonorrhea - an evolving disease of the new millennium

VIRULENCE FACTORS OF N. GONORRHOEAE Like many Gram-negative bacterial pathogens, N. gonorrhoeae possesses a wide range of ... Immunoglobin A (IgA) protease is another virulence factor in N. gonorrhoeae 83. Upon release from the cell, the protein ... Por1A-expressing gonococci also bind complement factor H more efficiently, and, as factor H down-regulates alternative ... I. Virulence genetically linked to clonal variation. . J Bacteriol. 1963;85(6):1274-1279. [PMC free article] [PubMed] ...
pubmedcentralcanada.ca/pmcc/articles/PMC5354566/

*  Prediction of molecular mimicry candidates in human pathogenic bacteria

... to known virulence factors from the MvirDB,27 suggesting possible roles in mimicry-mediated virulence. These include the ... Homology to virulence factors Sixty-one of 95 predicted mimics (non-redundant set) were detected as homologous (BLAST E-value ... Homology to known virulence factors. All candidate pathogen mimics were searched against the MvirDB27 database of known ... Zhou CE, Smith J, Lam M, Zemla A, Dyer MD, Slezak T. MvirDB--a microbial database of protein toxins, virulence factors and ...
pubmedcentralcanada.ca/pmcc/articles/PMC5359739/

*  Recent Articles | Settlers And Genetics & Genomics | The Scientist Magazine®| Page 23

Features Do Pathogens Gain Virulence as Hosts Become More Resistant? Emerging infections provide clues about how pathogens ... A recent paper challenges earlier findings that germline factors expressed in normal body cells influence life span in C. ... Questions Over C. elegans Life Span Factors. By Catherine Offord , June 1, 2016 ...
the-scientist.com/?articles.list/tagNo/1433,9/tags/settlers,genetics--amp--genomics/pageNo/23/

Virulence: Virulence is, by MeSH definition, the degree of pathogenicity within a group or species of parasites as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenicity of an organism - its ability to cause disease - is determined by its virulence factors.Ferric uptake regulator family: In molecular biology, the ferric uptake regulator (FUR) family of proteins includes metal ion uptake regulator proteins. These are responsible for controlling the intracellular concentration of iron in many bacteria.Coles PhillipsHaemolysin expression modulating protein family: In molecular biology, the haemolysin expression modulating protein family is a family of proteins. This family consists of haemolysin expression modulating protein (Hha) from Escherichia coli and its enterobacterial homologues, such as YmoA from Yersinia enterocolitica, and RmoA encoded on the R100 plasmid.AB toxin: The AB toxins are two-component protein complexes secreted by a number of pathogenic bacteria. They can be classified as Type III toxins because they interfere with internal cell function.Gentamicin protection assay: The gentamicin protection assay or survival assay or invasion assay is a method used in microbiology. It is used to quantify the ability of pathogenic bacteria to invade eukaryotic cells.Trimeric autotransporter adhesin: In molecular biology, trimeric autotransporter adhesins (TAAs), are proteins found on the outer membrane of Gram-negative bacteria. Bacteria use TAAs in order to infect their host cells via a process called cell adhesion.GyrA RNA motif: The gyrA RNA motif is a conserved RNA structure identified by bioinformatics. The RNAs are present in multiple species of bacteria within the order Pseudomonadales.Silent mutation: Silent mutations are mutations in DNA that do not significantly alter the phenotype of the organism in which they occur. Silent mutations can occur in non-coding regions (outside of genes or within introns), or they may occur within exons.Trans-activating crRNA: In molecular biology, trans-activating crRNA (tracrRNA) is a small trans-encoded RNA. It was first discovered in the human pathogen Streptococcus pyogenes.Bacterial outer membraneDeletion (genetics)List of strains of Escherichia coli: Escherichia coli is a well studied bacterium that was first identified by Theodor Escherich, after whom it was later named.Global microbial identifier: The genomic epidemiological database for global identification of microorganisms or global microbial identifier (GMI) is a platform for storing whole genome sequencing (WGS) data of microorganisms, for the identification of relevant genes and for the comparison of genomes to detect and track-and-trace infectious disease outbreaks and emerging pathogens. The database holds two types of information: 1) genomic information of microorganisms, linked to, 2) metadata of those microorganism such as epidemiological details.Protein primary structure: The primary structure of a peptide or protein is the linear sequence of its amino acid structural units, and partly comprises its overall biomolecular structure. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end.SaPI: SaPIs (Staphylococcus aureus or superantigen pathogenicity islands) are a family of mobile genetic elements resident in the genome of some strains of Staphylococcus aureus. Much like bacteriophages, SaPIs can be transferred to uninfected cells and integrate into the host chromosome.Escherichia coli (molecular biology): Escherichia coli (; commonly abbreviated E. coli) is a gammaproteobacterium commonly found in the lower intestine of warm-blooded organisms (endotherms).Fungicide use in the United States: A more accurate title for this page would be "Common plant pathogens to food crops in the United States".El Tor: El Tor is the name given to a particular strain of the bacterium Vibrio cholerae, the causative agent of cholera. Also known as V.DNA sequencer: A DNA sequencer is a scientific instrument used to automate the DNA sequencing process. Given a sample of DNA, a DNA sequencer is used to determine the order of the four bases: G (guanine), C (cytosine), A (adenine) and T (thymine).Pilin: Pilin refers to a class of fibrous proteins that are found in pilus structures in bacteria. Bacterial pili are used in the exchange of genetic material during bacterial conjugation, while a shorter type of appendages also made up of pilin, called fimbriae, are used as a cell adhesion mechanism.LcrV: In molecular biology, LcrV is a protein found in Yersinia pestis and several other bacterial species. It forms part of the Yersinia pestis virulence protein factors that also includes all Yop's, this used to stand for Yersinia outer protein, but the name has been kept out of convention.Thiol-activated cytolysin: Cholesterol-binding cytolysin, previously incorrectly known as 'thiol-activated' cytolysins Bacterial Disease Mechanisms: Michael Wilson, Rod McNab, Brian Henderson (2002)" are toxins produced by a variety of Gram-positive bacteria and are characterised by their ability to lyse cholesterol-containing membranes, their reversible inactivation by oxidation and their capacity to bind to cholesterol.Symmetry element: A symmetry element is a point of reference about which symmetry operations can take place. In particular, symmetry elements can be centers of inversion, axes of rotation and mirror planes.Cryptococcus neoformans: Cryptococcus neoformans is an encapsulated yeast and an obligate aerobe that can live in both plants and animals. Its teleomorph is Filobasidiella neoformans, a filamentous fungus belonging to the class Tremellomycetes.Signature-tagged mutagenesis: Signature-tagged mutagenesis (STM) is a genetic technique used to study gene function. Recent advances in genome sequencing have allowed us to catalogue a large variety of organisms' genomes, but the function of the genes they contain is still largely unknown.Cutaneous group B streptococcal infection: Cutaneous group B streptococcal infection may result in orbital cellulitis or facial erysipelas in neonates.Triparental mating: Triparental mating is a form of Bacterial conjugation where a conjugative plasmid present in one bacterial strain assists the transfer of a mobilizable plasmid present in a second bacterial strain into a third bacterial strain. Plasmids are introduced into bacteria for such purposes as transformation, cloning, or transposon mutagenesis.Bacterial capsule: The cell capsule is a very large structure of some prokaryotic cells, such as bacterial cells. It is a polysaccharide layer that lies outside the cell envelope of bacteria, and is thus deemed part of the outer envelope of a bacterial cell.Cholesterol-dependent cytolysin: Cholesterol-dependent cytolysins (CDC) are a family of β-barrel pore-forming exotoxins that are secreted by Gram-positive bacteria. CDC are secreted as water-soluble monomers of 50-70 kDa, that once bound to the target cell, will form a circular homo-oligomeric complex containing up to 40 monomers, although it is possible that some may incorporate more monomers.Branching order of bacterial phyla (Gupta, 2001): There are several models of the Branching order of bacterial phyla, one of these was proposed in 2001 by Gupta based on conserved indels or protein, termed "protein signatures", an alternative approach to molecular phylogeny. Some problematic exceptions and conflicts are present to these conserved indels, however, they are in agreement with several groupings of classes and phyla.Listeria monocytogenes: Listeria monocytogenes is the bacterium that causes the infection listeriosis. It is a facultative anaerobic bacterium, capable of surviving in the presence or absence of oxygen.Pseudomonas exotoxin: The Pseudomonas exotoxin (or exotoxin A) is an exotoxin produced by Pseudomonas aeruginosa.Acyl-homoserine-lactone synthase: Acyl-homoserine-lactone synthase (, acyl-homoserine lactone synthase, acyl homoserine lactone synthase, acyl-homoserinelactone synthase, acylhomoserine lactone synthase, AHL synthase, AHS, AHSL synthase, AhyI, AinS, AinS protein, autoinducer synthase, autoinducer synthesis protein rhlI, EsaI, ExpISCC1, ExpISCC3065, LasI, LasR, LuxI, LuxI protein, LuxM, N-acyl homoserine lactone synthase, RhlI, YspI, acyl-[acyl carrier protein]:S-adenosyl-L-methionine acyltranserase (lactone-forming, methylthioadenosine-releasing)) is an enzyme with system name acyl-(acyl-carrier protein):S-adenosyl-L-methionine acyltranserase (lactone-forming, methylthioadenosine-releasing). This eGross pathology: Gross pathology refers to macroscopic manifestations of disease in organs, tissues, and body cavities. The term is commonly used by anatomical pathologists to refer to diagnostically useful findings made during the gross examination portion of surgical specimen processing or an autopsy.Erosio interdigitalis blastomycetica: Erosio interdigitalis blastomycetica is a skin condition caused by a Candida albicans infection, characterized by an oval-shaped area of macerated white skin on the web between and extending onto the sides of the fingers.Median toxic dose: ==Introduction==Secretion: Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland. In contrast to excretion, the substance may have a certain function, rather than being a waste product.CDP-abequose synthase: CDP-abequose synthase (, rfbJ (gene)) is an enzyme with system name CDP-alpha-D-abequose:NADP+ 4-oxidoreductase. This enzyme catalyses the following chemical reactionPseudomonas infectionNif regulonYersinia enterocolitica: Yersinia enterocolitica is a Gram-negative bacillus-shaped bacterium, belonging to the family Enterobacteriaceae. Y.Septicemic plague: Septicemic (or septicaemic) plague is one of the three main forms of plague. It is caused by Yersinia pestis, a gram-negative species of bacterium.Operon: In genetics, an operon is a functioning unit of genomic DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo trans-splicing to create monocistronic mRNAs that are translated separately, i.Thermal cyclerHemolysis (microbiology): Hemolysis (or haemolysis in British English) is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms.Porphyromonas gingivalis: Porphyromonas gingivalis belongs to the phylum Bacteroidetes and is a nonmotile, Gram-negative, rod-shaped, anaerobic, pathogenic bacterium. It forms black colonies on blood agar.BiofilmBacitracinBordet-Gengou agar: Bordet-Gengou agar is a type of agar plate optimized to isolate Bordetella, containing blood, potato extract, and glycerol, with an antibiotic such as cephalexin or penicillin and sometimes nicotinamide.The potato extract provided nitrogen and vitamins, and potato starch absorbed fatty acids present in nasal secretions or collection-swab cotton that inhibited growth; glycerol was a carbon source.Composite transposon: A composite transposon is similar in function to simple transposons and Insertion Sequence (IS) elements in that it has protein coding DNA segments flanked by inverted, repeated sequences that can be recognized by transposase enzymes. A composite transposon, however, is flanked by two separate IS elements which may or may not be exact replicas.Phenotype microarray: The phenotype microarray approach is a technology for high-throughput phenotyping of cells.Vibrio vulnificus: Vibrio vulnificus is a species of Gram-negative, motile, curved, rod-shaped (Bacillus), Pathogenic bacteria of the genus Vibrio. Present in marine environments such as estuaries, brackish ponds, or coastal areas, V.Tingible body macrophage: A tingible body macrophage is a type of macrophage predominantly found in germinal centers, containing many phagocytized, apoptotic cells in various states of degradation, referred to as tingible bodies (tingible meaning stainable).Horst Ibelgaufts' COPE: Cytokines & Cells Online Pathfinder Encyclopaedia > tingible body macrophages Retrieved on June 27, 2010 Tingible body macrophages contain condensed chromatin fragments.Bacillus anthracis: Bacillus anthracis is the etiologic agent of anthrax—a common disease of livestock and, occasionally, of humans—and the only obligate pathogen within the genus Bacillus. B.Pathogenic Escherichia coli: Escherichia coli ( Anglicized to ; commonly abbreviated E. coli) is a gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms).CagA: Helicobacter pylori virulence factor CagA (cytotoxin-associated gene A) is a 120–145kDa protein encoded on the 40kb cag pathogenicity island (PAI). H.Shigella flexneri: Shigella flexneri is a species of Gram-negative bacteria in the genus Shigella that can cause diarrhea in humans. Several different serogroups of Shigella are described; S.Siderophore: Siderophores (Greek: "iron carrier") are small, high-affinity iron chelating compounds secreted by microorganisms such as bacteria, fungi and grasses.Miller, Marvin J.List of diseases (Y): This is a list of diseases starting with the letter "Y".CryptococcosisGene signature: A gene signature is a group of genes in a cell whose combined expression patternItadani H, Mizuarai S, Kotani H. Can systems biology understand pathway activation?Polysaccharide encapsulated bacteriaEscherichia coli O121: Escherichia coli O121 is a serotype of Escherichia coli, a species of bacteria that lives in the lower intestines of mammals.http://www.Enterohemorrhagic: Enterohemorrhagic Escherichia coli strain (EHEC) is the most common E. coli strain producing disease in U.Transfer-messenger RNA: Transfer-messenger RNA (abbreviated tmRNA, also known as 10Sa RNA and by its genetic name SsrA) is a bacterial RNA molecule with dual tRNA-like and messenger RNA-like properties. The tmRNA forms a ribonucleoprotein complex (tmRNP) together with Small Protein B (SmpB), Elongation Factor Tu (EF-Tu), and ribosomal protein S1.Heat-labile enterotoxin family: In molecular biology, the heat-labile enterotoxin family includes Escherichia coli heat-labile toxin and cholera toxin secreted by Vibrio cholerae. These toxins consist of an AB5 multimer structure, in which a pentamer of B chains has a membrane-binding function and an A chain is needed for enzymatic activity.Ligation-independent cloning: Ligation-independent cloning (LIC) is a form of molecular cloning that is able to be performed without the use of restriction endonucleases or DNA ligase. This allows genes that have restriction sites to be cloned without worry of chopping up the insert.HyphaQuellung reaction: The Quellung reaction is a biochemical reaction in which antibodies bind to the bacterial capsule of Streptococcus pneumoniae, Klebsiella pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Page 340 Escherichia coli, and Salmonella. The antibody reaction allows these species to be visualized under a microscope.

(1/5284) Import of DNA into mammalian nuclei by proteins originating from a plant pathogenic bacterium.

Import of DNA into mammalian nuclei is generally inefficient. Therefore, one of the current challenges in human gene therapy is the development of efficient DNA delivery systems. Here we tested whether bacterial proteins could be used to target DNA to mammalian cells. Agrobacterium tumefaciens, a plant pathogen, efficiently transfers DNA as a nucleoprotein complex to plant cells. Agrobacterium-mediated T-DNA transfer to plant cells is the only known example for interkingdom DNA transfer and is widely used for plant transformation. Agrobacterium virulence proteins VirD2 and VirE2 perform important functions in this process. We reconstituted complexes consisting of the bacterial virulence proteins VirD2, VirE2, and single-stranded DNA (ssDNA) in vitro. These complexes were tested for import into HeLa cell nuclei. Import of ssDNA required both VirD2 and VirE2 proteins. A VirD2 mutant lacking its C-terminal nuclear localization signal was deficient in import of the ssDNA-protein complexes into nuclei. Import of VirD2-ssDNA-VirE2 complexes was fast and efficient, and was shown to depended on importin alpha, Ran, and an energy source. We report here that the bacterium-derived and plant-adapted protein-DNA complex, made in vitro, can be efficiently imported into mammalian nuclei following the classical importin-dependent nuclear import pathway. This demonstrates the potential of our approach to enhance gene transfer to animal cells.  (+info)

(2/5284) Evidence for a structural motif in toxins and interleukin-2 that may be responsible for binding to endothelial cells and initiating vascular leak syndrome.

The dose-limiting toxicity of interleukin-2 (IL-2) and immunotoxin (IT) therapy in humans is vascular leak syndrome (VLS). VLS has a complex etiology involving damage to vascular endothelial cells (ECs), extravasation of fluids and proteins, interstitial edema, and organ failure. IL-2 and ITs prepared with the catalytic A chain of the plant toxin, ricin (RTA), and other toxins, damage human ECs in vitro and in vivo. Damage to ECs may initiate VLS; if this damage could be avoided without losing the efficacy of ITs or IL-2, larger doses could be administered. In this paper, we provide evidence that a three amino acid sequence motif, (x)D(y), in toxins and IL-2 damages ECs. Thus, when peptides from RTA or IL-2 containing this sequence motif are coupled to mouse IgG, they bind to and damage ECs both in vitro and, in the case of RTA, in vivo. In contrast, the same peptides with a deleted or mutated sequence do not. Furthermore, the peptide from RTA attached to mouse IgG can block the binding of intact RTA to ECs in vitro and vice versa. In addition, RTA, a fragment of Pseudomonas exotoxin A (PE38-lys), and fibronectin also block the binding of the mouse IgG-RTA peptide to ECs, suggesting that an (x)D(y) motif is exposed on all three molecules. Our results suggest that deletions or mutations in this sequence or the use of nondamaging blocking peptides may increase the therapeutic index of both IL-2, as well as ITs prepared with a variety of plant or bacterial toxins.  (+info)

(3/5284) Heparin-binding EGF-like growth factor interacts with mouse blastocysts independently of ErbB1: a possible role for heparan sulfate proteoglycans and ErbB4 in blastocyst implantation.

Blastocyst implantation requires molecular and cellular interactions between the uterine luminal epithelium and blastocyst trophectoderm. We have previously shown that heparin-binding EGF-like growth factor (HB-EGF) is induced in the mouse luminal epithelium solely at the site of blastocyst apposition at 16:00 hours on day 4 of pregnancy prior to the attachment reaction (22:00-23:00 hours), and that HB-EGF promotes blastocyst growth, zona-hatching and trophoblast outgrowth. To delineate which EGF receptors participate in blastocyst activation, the toxicity of chimeric toxins composed of HB-EGF or TGF-(&agr;) coupled to Pseudomonas exotoxin (PE) were used as measures of receptor expression. TGF-(&agr;) or HB-EGF binds to EGF-receptor (ErbB1), while HB-EGF, in addition, binds to ErbB4. The results indicate that ErbB1 is inefficient in mediating TGF-(&agr;)-PE or HB-EGF-PE toxicity as follows: (i) TGF-(&agr;)-PE was relatively inferior in killing blastocysts, 100-fold less than HB-EGF-PE, (ii) analysis of blastocysts isolated from cross-bred egfr+/- mice demonstrated that HB-EGF-PE, but not TGF-(&agr;)-PE, killed egfr-/- blastocysts, and (iii) blastocysts that survived TGF-(&agr;)-PE were nevertheless killed by HB-EGF-PE. HB-EGF-PE toxicity was partially mediated by cell surface heparan sulfate proteoglycans (HSPG), since a peptide corresponding to the heparin-binding domain of HB-EGF as well as heparitinase treatment protected the blastocysts from the toxic effects of HB-EGF-PE by about 40%. ErbB4 is a candidate for being an HB-EGF-responsive receptor since RT-PCR analysis demonstrated that day 4 mouse blastocysts express two different erbB4 isoforms and immunostaining with anti-ErbB4 antibodies confirmed that ErbB4 protein is expressed at the apical surface of the trophectoderm cells. It is concluded that (i) HB-EGF interacts with the blastocyst cell surface via high-affinity receptors other than ErbB1, (ii) the HB-EGF interaction with high-affinity blastocysts receptors is regulated by heparan sulfate, and (iii) ErbB4 is a candidate for being a high-affinity receptor for HB-EGF on the surface of implantation-competent blastocysts.  (+info)

(4/5284) Prevention of graft-versus-host disease (GVHD) by elimination of recipient-reactive donor T cells with recombinant toxins that target the interleukin 2 (IL-2) receptor.

Graft-versus-host disease (GVHD), due to the presence of recipient-reactive T cells, limits the usefulness of bone marrow transplantation (BMT) and is a major contributor to patient mortality. To prevent GVHD, murine and human T cells were activated by antigen or mitogens and treated with a genetically engineered form of Pseudomonas exotoxin A (PE) directed against the IL-2 receptor. Treatment with the chimeric toxin eliminated alloreactive cytotoxic T lymphocytes (CTL) as determined by cytotoxicity and mixed lymphocyte culture assays. Precursor frequencies of alloreactive cytotoxic T cells and proliferative T cells were reduced up to 100-fold as shown by limiting dilution assays. Flow cytometric analyses revealed that treatment with the chimeric toxin completely eliminated CD25+ cells from the cultures. Toxin treatment had no significant effect on hematopoietic stem and progenitor cells as determined in vitro by colony-forming assays and in vivo by long-term hematopoietic recovery after 950 rad irradiation. Toxin treatment decreased GVHD in transplanted mice to less than 10% (as compared to 88% in untreated controls). Thus, it is possible to prevent life-threatening GVHD after BMT by using a CD25 receptor-directed toxin to eliminate host-reactive T cells from bone marrow grafts.  (+info)

(5/5284) Suppression of metastasis formation by a recombinant single chain antibody-toxin targeted to full-length and oncogenic variant EGF receptors.

Cytotoxic strategies which are directed to tumor-associated antigens might be most beneficial for cancer patients with minimal tumor load such as in an adjuvant setting after initial therapy. We have recently described a highly potent single chain antibody-toxin, scFv(14E1)-ETA, which consists of the variable domains of the antibody 14E1 genetically fused to a truncated form of Pseudomonas exotoxin A. ScFv(14E1)-ETA specifically recognizes the human epidermal growth factor receptor (EGFR) and the oncogenically activated receptor variant EGFRvIII, which have been implicated in the development of various human malignancies. Here we have investigated the antimetastatic activity of bacterially expressed scFv(14E1)-ETA and its disulfide-stabilized derivative ds-scFv(14E1)-ETA in a novel model for disseminated disease which is based on murine renal carcinoma cells subsequently transfected with the E. coli beta-galactosidase gene, and human full-length or variant EGFR cDNAs. Intravenous injection of these Renca-lacZ/EGFR and Renca-lacZ/EGFRvIII cells in syngenic Balb/c mice led to the formation of pulmonary metastases which were readily detectable upon excision of the lungs and X-gal staining. Systemic treatment of mice with scFv(14E1)-ETA resulted in the complete suppression of Renca-lacZ/EGFRvIII metastasis formation and drastically reduced the number of pulmonary Renca-lacZ/EGFR tumor nodules. The ds-scFv(14E1)-ETA derivative where the antibody variable regions are connected by an artificial disulfide bond displayed improved thermal stability at physiological temperature but due to reduced cytotoxic activity was less potent than the original scFv(14E1)-ETA in metastasis suppression.  (+info)

(6/5284) Endoprotease PACE4 is Ca2+-dependent and temperature-sensitive and can partly rescue the phenotype of a furin-deficient cell strain.

PACE4 is a member of the eukaryotic subtilisin-like endoprotease family. The expression of human PACE4 in RPE.40 cells (furin-null mutants derived from Chinese hamster ovary K1 cells) resulted in the rescue of a number of wild-type characteristics, including sensitivity to Sindbis virus and the ability to process the low-density-lipoprotein receptor-related protein. Expression of PACE4 in these cells failed to restore wild-type sensitivity to Pseudomonas exotoxin A. Co-expression of human PACE4 in these cells with either a secreted form of the human insulin pro-receptor or the precursor form of von Willebrand factor resulted in both proproteins being processed; RPE.40 cells were unable to process either precursor protein in the absence of co-expressed PACE4. Northern analysis demonstrated that untransfected RPE.40 cells express mRNA species for four PACE4 isoforms, suggesting that any endogenous PACE4 proteins produced by these cells are either non-functional or sequestered in a compartment outside of the secretory pathway. In experiments in vitro, PACE4 processed diphtheria toxin and anthrax toxin protective antigen, but not Pseudomonas exotoxin A. The activity of PACE4 in vitro was Ca2+-dependent and, unlike furin, was sensitive to temperature changes between 22 and 37 degrees C. RPE.40 cells stably expressing human PACE4 secreted an endoprotease with the same Ca2+ dependence and temperature sensitivity as that observed in membrane fractions of these cells assayed in vitro. These results, in conjunction with other published work, demonstrate that PACE4 is an endoprotease with more stringent substrate specificity and more limited operating parameters than furin.  (+info)

(7/5284) Extrahepatic synthesis of plasminogen in the human cornea is up-regulated by interleukins-1alpha and -1beta.

The avascular cornea has limited access to plasma proteins, including plasminogen, a protein that is synthesized by the liver and supplied to most tissues via the blood. Recent experiments by others using plasminogen-deficient mice revealed the importance of plasmin, the active form of plasminogen, for the maintenance of the normal cornea and for corneal wound healing [Kao, Kao, Bugge, Kaufman, Kombrinck, Converse, Good and Degan (1998) Invest. Ophthalmol. Vis. Sci. 39, 502-508; Drew, Kaufman, Kombrinck, Danton, Daugherty, Degen and Bugge (1998) Blood 91, 1616-1624]. In the present experiments, plasmin was identified as a major serine proteinase in the human cornea. The major plasminogen and plasmin forms on non-reducing zymograms and Western blots had Mr values of 76x10(3) and 85x10(3), with minor forms of Mr 200x10(3), 135x10(3), 68x10(3) and 45x10(3). Angiostatin-like peptides with Mrs of 48x10(3), 45x10(3) and 38x10(3) were observed which bound to lysine-Sepharose and reacted with anti-plasminogen monoclonal antibodies directed towards kringle domains 1-3 of plasminogen. The cornea contained 1.1+/-0.15 microgram of plasminogen+plasmin/cornea, or 0.54+/-0.05 microgram of plasminogen+plasmin/mg of protein. Cornea conditioned medium contained nine times the amount of plasminogen+plasmin that could be extracted from the cornea. These data suggested that corneal cells, unlike most extrahepatic cells, synthesize plasminogen. The synthesis of plasminogen by the cornea was confirmed by immunoprecipitation of metabolically labelled plasminogen, sequencing of its cDNA obtained by reverse transcriptase-PCR and inhibition of protein synthesis. Interleukins-1alpha and -1beta stimulated corneal plasminogen synthesis 2-3-fold; however, interleukin-6 decreased corneal plasminogen synthesis by approx. 40% at early times after addition of the cytokine. By 24 h of culture, no differences were noted in the presence and absence of interleukin-6. Thus the cornea can synthesize plasminogen and regulate its synthesis in response to its environment, including cytokines induced in the cornea by injury and inflammation. Therefore the cornea can control the amount of plasminogen, the precursor of both plasmin and angiostatin.  (+info)

(8/5284) Molecular characterization of a flagellar export locus of Helicobacter pylori.

Motility of Helicobacter species has been shown to be essential for successful colonization of the host. We have investigated the organization of a flagellar export locus in Helicobacter pylori. A 7-kb fragment of the H. pylori CCUG 17874 genome was cloned and sequenced, revealing an operon comprising an open reading frame of unknown function (ORF03), essential housekeeping genes (ileS and murB), flagellar export genes (fliI and fliQ), and a homolog to a gene implicated in virulence factor transport in other pathogens (virB11). A promoter for this operon, showing similarity to the Escherichia coli sigma70 consensus, was identified by primer extension. Cotranscription of the genes in the operon was demonstrated by reverse transcription-PCR, and transcription of virB11, fliI, fliQ, and murB was detected in human or mouse biopsies obtained from infected hosts. The genetic organization of this locus was conserved in a panel of H. pylori clinical isolates. Engineered fliI and fliQ mutant strains were completely aflagellate and nonmotile, whereas a virB11 mutant still produced flagella. The fliI and fliQ mutant strains produced reduced levels of flagellin and the hook protein FlgE. Production of OMP4, a member of the outer membrane protein family identified in H. pylori 26695, was reduced in both the virB11 mutant and the fliI mutant, suggesting related functions of the virulence factor export protein (VirB11) and the flagellar export component (FliI).  (+info)



genes


  • PAI provides P. aeruginosa with a means of cell-to-cell communication that is required for the expression of virulence genes and may provide a target for therapeutic approaches. (sciencemag.org)
  • Antibiotic-resistance genes, as well as other virulence factor genes, are easily passed between bacterial cells through horizontal gene transfer. (solutioninn.com)