Enterococcus faecalis
A species of gram-positive, coccoid bacteria commonly isolated from clinical specimens and the human intestinal tract. Most strains are nonhemolytic.
Enterococcus
A genus of gram-positive, coccoid bacteria consisting of organisms causing variable hemolysis that are normal flora of the intestinal tract. Previously thought to be a member of the genus STREPTOCOCCUS, it is now recognized as a separate genus.
Enterococcus faecium
Gram-Positive Bacterial Infections
Infections caused by bacteria that retain the crystal violet stain (positive) when treated by the gram-staining method.
Vancomycin Resistance
Carbon-Oxygen Ligases
Vancomycin
Antibacterial obtained from Streptomyces orientalis. It is a glycopeptide related to RISTOCETIN that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear.
Anti-Bacterial Agents
Substances that reduce the growth or reproduction of BACTERIA.
Microbial Sensitivity Tests
Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).
Drug Resistance, Microbial
Ampicillin Resistance
Nonsusceptibility of a microbe to the action of ampicillin, a penicillin derivative that interferes with cell wall synthesis.
Conjugation, Genetic
A parasexual process in BACTERIA; ALGAE; FUNGI; and ciliate EUKARYOTA for achieving exchange of chromosome material during fusion of two cells. In bacteria, this is a uni-directional transfer of genetic material; in protozoa it is a bi-directional exchange. In algae and fungi, it is a form of sexual reproduction, with the union of male and female gametes.
Bacteriocins
DNA, Bacterial
Deoxyribonucleic acid that makes up the genetic material of bacteria.
Teicoplanin
Glycopeptide antibiotic complex from Actinoplanes teichomyceticus active against gram-positive bacteria. It consists of five major components each with a different fatty acid moiety.
Gentamicins
A complex of closely related aminoglycosides obtained from MICROMONOSPORA purpurea and related species. They are broad-spectrum antibiotics, but may cause ear and kidney damage. They act to inhibit PROTEIN BIOSYNTHESIS.
Virginiamycin
A cyclic polypeptide antibiotic complex from Streptomyces virginiae, S. loidensis, S. mitakaensis, S. pristina-spiralis, S. ostreogriseus, and others. It consists of 2 major components, VIRGINIAMYCIN FACTOR M1 and virginiamycin Factor S1. It is used to treat infections with gram-positive organisms and as a growth promoter in cattle, swine, and poultry.
Oxazolidinones
Acetamides
Gram-Positive Cocci
Coccus-shaped bacteria that retain the crystal violet stain when treated by Gram's method.
Drug Resistance, Bacterial
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.
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.
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.
Endocarditis, Bacterial
Genes, Bacterial
The functional hereditary units of BACTERIA.
Glycopeptides
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.
Daptomycin
A cyclic lipopeptide antibiotic that inhibits GRAM-POSITIVE BACTERIA.
Pheromones
Lactococcus
A genus of gram-positive, coccoid bacteria mainly isolated from milk and milk products. These bacteria are also found in plants and nonsterile frozen and dry foods. Previously thought to be a member of the genus STREPTOCOCCUS (group N), it is now recognized as a separate genus.
Sequence Analysis, DNA
Plasmids
Bacteria
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
Streptococcaceae
A family of gram-positive non-sporing bacteria including many parasitic, pathogenic, and saprophytic forms.
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.
Ampicillin
Feces
Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
Cheese
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.
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.
Anti-Infective Agents
Gram-Negative Bacteria
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.
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.
Gene Expression Regulation, Bacterial
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
Streptogramins
RNA, Ribosomal, 16S
Aminoglycosides
Base Sequence
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.
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.
Peptide Synthases
Amino Acid Sequence
Tetracycline Resistance
Nonsusceptibility of bacteria to the action of TETRACYCLINE which inhibits aminoacyl-tRNA binding to the 30S ribosomal subunit during protein synthesis.
Food Microbiology
Streptogramin A
A specific streptogramin group A antibiotic produced by Streptomyces graminofaciens and other bacteria.
Muramoylpentapeptide Carboxypeptidase
Root Canal Irrigants
Chemicals used mainly to disinfect root canals after pulpectomy and before obturation. The major ones are camphorated monochlorophenol, EDTA, formocresol, hydrogen peroxide, metacresylacetate, and sodium hypochlorite. Root canal irrigants include also rinsing solutions of distilled water, sodium chloride, etc.
Drug Resistance, Multiple, Bacterial
Dental Pulp Cavity
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)
Penicillin-Binding Proteins
Bacterial proteins that share the property of binding irreversibly to PENICILLINS and other ANTIBACTERIAL AGENTS derived from LACTAMS. The penicillin-binding proteins are primarily enzymes involved in CELL WALL biosynthesis including MURAMOYLPENTAPEPTIDE CARBOXYPEPTIDASE; PEPTIDE SYNTHASES; TRANSPEPTIDASES; and HEXOSYLTRANSFERASES.
Lactobacillus
A genus of gram-positive, microaerophilic, rod-shaped bacteria occurring widely in nature. Its species are also part of the many normal flora of the mouth, intestinal tract, and vagina of many mammals, including humans. Pathogenicity from this genus is rare.
Gelatinases
Peptidoglycan
Peptidoglycan is a complex, cross-linked polymer of carbohydrates and peptides that forms the rigid layer of the bacterial cell wall, providing structural support and protection while contributing to the bacterium's susceptibility or resistance to certain antibiotics.
Peptidyl Transferases
DNA, Ribosomal
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.
Serine-Type D-Ala-D-Ala Carboxypeptidase
A carboxypeptidase that is specific for proteins that contain two ALANINE residues on their C-terminal. Enzymes in this class play an important role in bacterial CELL WALL biosynthesis.
Bacterial Load
Measurable quantity of bacteria in an object, organism, or organism compartment.
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.
Sex Attractants
Microbial Viability
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.
Penicillins
A group of antibiotics that contain 6-aminopenicillanic acid with a side chain attached to the 6-amino group. The penicillin nucleus is the chief structural requirement for biological activity. The side-chain structure determines many of the antibacterial and pharmacological characteristics. (Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1065)
RNA, Bacterial
Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.
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).
Fluoroquinolones
A group of QUINOLONES with at least one fluorine atom and a piperazinyl group.
Bacteriological Techniques
Techniques used in studying bacteria.
Staphylococcus
A genus of gram-positive, facultatively anaerobic, coccoid bacteria. Its organisms occur singly, in pairs, and in tetrads and characteristically divide in more than one plane to form irregular clusters. Natural populations of Staphylococcus are found on the skin and mucous membranes of warm-blooded animals. Some species are opportunistic pathogens of humans and animals.
Multilocus Sequence Typing
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)
Sodium Hypochlorite
Erythromycin
A bacteriostatic antibiotic macrolide produced by Streptomyces erythreus. Erythromycin A is considered its major active component. In sensitive organisms, it inhibits protein synthesis by binding to 50S ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins.
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.
Bacterial Infections
Infections by bacteria, general or unspecified.
Probiotics
Live microbial DIETARY SUPPLEMENTS which beneficially affect the host animal by improving its intestinal microbial balance. Antibiotics and other related compounds are not included in this definition. In humans, lactobacilli are commonly used as probiotics, either as single species or in mixed culture with other bacteria. Other genera that have been used are bifidobacteria and streptococci. (J. Nutr. 1995;125:1401-12)
Nucleic Acid Hybridization
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
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.
Dental Pulp Diseases
Poultry
Domesticated birds raised for food. It typically includes CHICKENS; TURKEYS, DUCKS; GEESE; and others.
Minocycline
A TETRACYCLINE analog, having a 7-dimethylamino and lacking the 5 methyl and hydroxyl groups, which is effective against tetracycline-resistant STAPHYLOCOCCUS infections.
Gastrointestinal Tract
DNA Fingerprinting
A technique for identifying individuals of a species that is based on the uniqueness of their DNA sequence. Uniqueness is determined by identifying which combination of allelic variations occur in the individual at a statistically relevant number of different loci. In forensic studies, RESTRICTION FRAGMENT LENGTH POLYMORPHISM of multiple, highly polymorphic VNTR LOCI or MICROSATELLITE REPEAT loci are analyzed. The number of loci used for the profile depends on the ALLELE FREQUENCY in the population.
Antibiosis
Peritonitis
INFLAMMATION of the PERITONEUM lining the ABDOMINAL CAVITY as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the PERITONEAL CAVITY via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the ABDOMINAL CAVITY itself through RUPTURE or ABSCESS of intra-abdominal organs.
Disk Diffusion Antimicrobial Tests
Genome, Bacterial
The genetic complement of a BACTERIA as represented in its DNA.
Listeria
Streptomycin
Bacteria, Aerobic
Aerobic bacteria are types of microbes that require oxygen to grow and reproduce, and use it in the process of respiration to break down organic matter and produce energy, often found in environments where oxygen is readily available such as the human body's skin, mouth, and intestines.
Bacitracin
A complex of cyclic peptide antibiotics produced by the Tracy-I strain of Bacillus subtilis. The commercial preparation is a mixture of at least nine bacitracins with bacitracin A as the major constituent. It is used topically to treat open infections such as infected eczema and infected dermal ulcers. (From Goodman and Gilman, The Pharmacological Basis of Therapeutics, 8th ed, p1140)
Phenotype
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
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.
Chlorhexidine
Pulpitis
Inflammation of the DENTAL PULP, usually due to bacterial infection in dental caries, tooth fracture, or other conditions causing exposure of the pulp to bacterial invasion. Chemical irritants, thermal factors, hyperemic changes, and other factors may also cause pulpitis.
Cephalosporins
Chromosomes, Bacterial
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.
Chickens
Anti-Infective Agents, Local
Tyrosine Decarboxylase
Naphthyridines
Naphthyridines are a class of heterocyclic organic compounds containing a naphthyridine nucleus, which is a polycyclic aromatic hydrocarbon made up of two benzene rings fused to a pyridine ring, and they have been studied for their potential pharmacological properties, including as antimicrobial, antiviral, and anticancer agents.
RNA, Ribosomal, 23S
Periapical Periodontitis
Streptococcal Infections
Calcium Hydroxide
Molecular Epidemiology
Uridine Diphosphate N-Acetylmuramic Acid
A nucleoside diphosphate sugar which is formed from UDP-N-acetylglucosamine and phosphoenolpyruvate. It serves as the building block upon which peptidoglycan is formed.
Cloning, Molecular
Fermentation
Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.
Enterobacteriaceae
A family of gram-negative, facultatively anaerobic, rod-shaped bacteria that do not form endospores. Its organisms are distributed worldwide with some being saprophytes and others being plant and animal parasites. Many species are of considerable economic importance due to their pathogenic effects on agriculture and livestock.
Bacteriolysis
Lactococcus lactis
A non-pathogenic species of LACTOCOCCUS found in DAIRY PRODUCTS and responsible for the souring of MILK and the production of LACTIC ACID.
Lactobacillaceae
A family of gram-positive bacteria found regularly in the mouth and intestinal tract of man and other animals, in food and dairy products, and in fermenting vegetable juices. A few species are highly pathogenic.
Agar
A complex sulfated polymer of galactose units, extracted from Gelidium cartilagineum, Gracilaria confervoides, and related red algae. It is used as a gel in the preparation of solid culture media for microorganisms, as a bulk laxative, in making emulsions, and as a supporting medium for immunodiffusion and immunoelectrophoresis.
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.
N-Acetylmuramoyl-L-alanine Amidase
An autolytic enzyme bound to the surface of bacterial cell walls. It catalyzes the hydrolysis of the link between N-acetylmuramoyl residues and L-amino acid residues in certain cell wall glycopeptides, particularly peptidoglycan. EC 3.5.1.28.
Drug Therapy, Combination
Water Microbiology
The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.
Acetoin
A product of fermentation. It is a component of the butanediol cycle in microorganisms. In mammals it is oxidized to carbon dioxide.
Tylosin
Genotype
Serum Bactericidal Test
Method of measuring the bactericidal activity contained in a patient's serum as a result of antimicrobial therapy. It is used to monitor the therapy in BACTERIAL ENDOCARDITIS; OSTEOMYELITIS and other serious bacterial infections. As commonly performed, the test is a variation of the broth dilution test. This test needs to be distinguished from testing of the naturally occurring BLOOD BACTERICIDAL ACTIVITY.
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.
Lincosamides
A family of LINCOMYCIN-related glycosides that contain a pyrrolidine ring linked via an amide-bond to a pyranose moiety. Individual members of this family are defined by the arrangement of specific constituent groups on the lyncomycin molecule. Many lincosamides are ANTIBIOTICS produced by a variety STREPTOMYCES species.
Genes, rRNA
Infection Control
Sequence Homology, Amino Acid
Quinolones
Cell Wall
Open Reading Frames
Endocarditis
Inflammation of the inner lining of the heart (ENDOCARDIUM), the continuous membrane lining the four chambers and HEART VALVES. It is often caused by microorganisms including bacteria, viruses, fungi, and rickettsiae. Left untreated, endocarditis can damage heart valves and become life-threatening.
Cluster Analysis
A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.
Evaluation Studies as Topic
Endophthalmitis
Penicillin Resistance
Nonsusceptibility of an organism to the action of penicillins.
Bacteria, Anaerobic
'Anaerobic Bacteria' are types of bacteria that do not require oxygen for growth and can often cause diseases in humans, including dental caries, gas gangrene, and tetanus, among others.
Potassium-Hydrogen Antiporters
Imipenem
Semisynthetic thienamycin that has a wide spectrum of antibacterial activity against gram-negative and gram-positive aerobic and anaerobic bacteria, including many multiresistant strains. It is stable to beta-lactamases. Clinical studies have demonstrated high efficacy in the treatment of infections of various body systems. Its effectiveness is enhanced when it is administered in combination with CILASTATIN, a renal dipeptidase inhibitor.
Chromogenic Compounds
Colorless, endogenous or exogenous pigment precursors that may be transformed by biological mechanisms into colored compounds; used in biochemical assays and in diagnosis as indicators, especially in the form of enzyme substrates. Synonym: chromogens (not to be confused with pigment-synthesizing bacteria also called chromogens).
Root Canal Filling Materials
Poultry Products
Food products manufactured from poultry.
Aminoacyltransferases
Nisin
A 34-amino acid polypeptide antibiotic produced by Streptococcus lactis. It has been used as a food preservative in canned fruits and vegetables, and cheese.
Gram-Negative Bacterial Infections
Infections caused by bacteria that show up as pink (negative) when treated by the gram-staining method.