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.Bacillus: A genus of BACILLACEAE that are spore-forming, rod-shaped cells. Most species are saprophytic soil forms with only a few species being pathogenic.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Gram-Negative Bacteria: Bacteria which lose crystal violet stain but are stained pink when treated by Gram's method.Gram-Positive Bacteria: Bacteria which retain the crystal violet stain when treated by Gram's method.Bacterial Proteins: Proteins found in any species of bacterium.Bacteria, AnaerobicMolecular 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.Micrococcus: A genus of gram-positive, spherical bacteria found in soils and fresh water, and frequently on the skin of man and other animals.Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).Cycloserine: Antibiotic substance produced by Streptomyces garyphalus.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.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.Protein Disulfide-Isomerases: Sulfur-sulfur bond isomerases that catalyze the rearrangement of disulfide bonds within proteins during folding. Specific protein disulfide-isomerase isoenzymes also occur as subunits of PROCOLLAGEN-PROLINE DIOXYGENASE.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.Bacteria, AerobicStreptococcus mutans: A polysaccharide-producing species of STREPTOCOCCUS isolated from human dental plaque.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Genes, Bacterial: The functional hereditary units of BACTERIA.Polyisoprenyl Phosphates: Phosphoric or pyrophosphoric acid esters of polyisoprenoids.Enterococcus faecalis: A species of gram-positive, coccoid bacteria commonly isolated from clinical specimens and the human intestinal tract. Most strains are nonhemolytic.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).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.Bacteriological Techniques: Techniques used in studying bacteria.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Drug Resistance, Microbial: The ability of microorganisms, especially 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).Bacillus subtilis: A species of gram-positive bacteria that is a common soil and water saprophyte.DNA, Ribosomal: DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.Peptide Synthases: Ligases that catalyze the joining of adjacent AMINO ACIDS by the formation of carbon-nitrogen bonds between their carboxylic acid groups and amine groups.PeptidoglycanAgar: 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.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.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.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.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.Pharmacology: The study of the origin, nature, properties, and actions of drugs and their effects on living organisms.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Water Microbiology: The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.Novobiocin: An antibiotic compound derived from Streptomyces niveus. It has a chemical structure similar to coumarin. Novobiocin binds to DNA gyrase, and blocks adenosine triphosphatase (ATPase) activity. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p189)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.ATP-Binding Cassette Transporters: A family of MEMBRANE TRANSPORT PROTEINS that require ATP hydrolysis for the transport of substrates across membranes. The protein family derives its name from the ATP-binding domain found on the protein.Reducing Agents: Materials that add an electron to an element or compound, that is, decrease the positiveness of its valence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)L Forms: Bacterial variants, unable to form a complete cell wall, which are formed in cultures by various bacteria; granules (L bodies) appear, unite, and grow into amorphous bodies which multiply and give rise to bacterial cells morphologically indistinguishable from the parent strain.Pharynx: A funnel-shaped fibromuscular tube that conducts food to the ESOPHAGUS, and air to the LARYNX and LUNGS. It is located posterior to the NASAL CAVITY; ORAL CAVITY; and LARYNX, and extends from the SKULL BASE to the inferior border of the CRICOID CARTILAGE anteriorly and to the inferior border of the C6 vertebra posteriorly. It is divided into the NASOPHARYNX; OROPHARYNX; and HYPOPHARYNX (laryngopharynx).Gram-Negative Aerobic Bacteria: A large group of aerobic bacteria which show up as pink (negative) when treated by the gram-staining method. This is because the cell walls of gram-negative bacteria are low in peptidoglycan and thus have low affinity for violet stain and high affinity for the pink dye safranine.Gram-Negative Anaerobic Bacteria: A large group of anaerobic bacteria which show up as pink (negative) when treated by the Gram-staining method.Bacterial Physiological Phenomena: Physiological processes and properties of BACTERIA.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.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.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.Potassium Isotopes: Stable potassium atoms that have the same atomic number as the element potassium, but differ in atomic weight. K-41 is a stable potassium isotope.Soil Microbiology: The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.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.Penicillin G: A penicillin derivative commonly used in the form of its sodium or potassium salts in the treatment of a variety of infections. It is effective against most gram-positive bacteria and against gram-negative cocci. It has also been used as an experimental convulsant because of its actions on GAMMA-AMINOBUTYRIC ACID mediated synaptic transmission.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Spores, Bacterial: Heat and stain resistant, metabolically inactive bodies formed within the vegetative cells of bacteria of the genera Bacillus and Clostridium.Pyrophosphatases: A group of enzymes within the class EC 3.6.1.- that catalyze the hydrolysis of diphosphate bonds, chiefly in nucleoside di- and triphosphates. They may liberate either a mono- or diphosphate. EC 3.6.1.-.Anti-Infective Agents, Local: Substances used on humans and other animals that destroy harmful microorganisms or inhibit their activity. They are distinguished from DISINFECTANTS, which are used on inanimate objects.Sulfur-Reducing Bacteria: A group of gram-negative, anaerobic bacteria that is able to oxidize acetate completely to carbon dioxide using elemental sulfur as the electron acceptor.Seawater: The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.Food Additives: Substances which are of little or no nutritive value, but are used in the processing or storage of foods or animal feed, especially in the developed countries; includes ANTIOXIDANTS; FOOD PRESERVATIVES; FOOD COLORING AGENTS; FLAVORING AGENTS; ANTI-INFECTIVE AGENTS (both plain and LOCAL); VEHICLES; EXCIPIENTS and other similarly used substances. Many of the same substances are PHARMACEUTIC AIDS when added to pharmaceuticals rather than to foods.Dithionitrobenzoic Acid: A standard reagent for the determination of reactive sulfhydryl groups by absorbance measurements. It is used primarily for the determination of sulfhydryl and disulfide groups in proteins. The color produced is due to the formation of a thio anion, 3-carboxyl-4-nitrothiophenolate.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.Clostridium perfringens: The most common etiologic agent of GAS GANGRENE. It is differentiable into several distinct types based on the distribution of twelve different toxins.Polymyxin B: A mixture of polymyxins B1 and B2, obtained from Bacillus polymyxa strains. They are basic polypeptides of about eight amino acids and have cationic detergent action on cell membranes. Polymyxin B is used for infections with gram-negative organisms, but may be neurotoxic and nephrotoxic.Neomycin: Antibiotic complex produced by Streptomyces fradiae. It is composed of neomycins A, B, and C. It acts by inhibiting translation during protein synthesis.Bacteriocins: Substances elaborated by specific strains of bacteria that are lethal against other strains of the same or related species. They are protein or lipopolysaccharide-protein complexes used in taxonomy studies of bacteria.Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Genes, rRNA: Genes, found in both prokaryotes and eukaryotes, which are transcribed to produce the RNA which is incorporated into RIBOSOMES. Prokaryotic rRNA genes are usually found in OPERONS dispersed throughout the GENOME, whereas eukaryotic rRNA genes are clustered, multicistronic transcriptional units.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.Symbiosis: The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.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.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)Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Chemical Fractionation: Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Base Composition: The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.Streptococcal Infections: Infections with bacteria of the genus STREPTOCOCCUS.Biodegradation, Environmental: Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.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.Pharyngitis: Inflammation of the throat (PHARYNX).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.Pseudomonas: A genus of gram-negative, aerobic, rod-shaped bacteria widely distributed in nature. Some species are pathogenic for humans, animals, and plants.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.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.Protoplasts: The protoplasm and plasma membrane of plant, fungal, bacterial or archaeon cells without the CELL WALL.Kinetics: The rate dynamics in chemical or physical systems.Hemolysis: The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.Fresh Water: Water containing no significant amounts of salts, such as water from RIVERS and LAKES.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.Multienzyme Complexes: Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES.Gammaproteobacteria: A group of the proteobacteria comprised of facultatively anaerobic and fermentative gram-negative bacteria.Reagent Strips: Narrow pieces of material impregnated or covered with a substance used to produce a chemical reaction. The strips are used in detecting, measuring, producing, etc., other substances. (From Dorland, 28th ed)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)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.Bacterial Infections: Infections by bacteria, general or unspecified.Diphosphates: Inorganic salts of phosphoric acid that contain two phosphate groups.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.Geologic Sediments: A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)Proteobacteria: A phylum of bacteria consisting of the purple bacteria and their relatives which form a branch of the eubacterial tree. This group of predominantly gram-negative bacteria is classified based on homology of equivalent nucleotide sequences of 16S ribosomal RNA or by hybridization of ribosomal RNA or DNA with 16S and 23S ribosomal RNA.Bacteroides: A genus of gram-negative, anaerobic, rod-shaped bacteria. Its organisms are normal inhabitants of the oral, respiratory, intestinal, and urogenital cavities of humans, animals, and insects. Some species may be pathogenic.Aerobiosis: Life or metabolic reactions occurring in an environment containing oxygen.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.Metals: Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)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.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.Vancomycin Resistance: Nonsusceptibility of bacteria to the action of VANCOMYCIN, an inhibitor of cell wall synthesis.Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.Betaproteobacteria: A class in the phylum PROTEOBACTERIA comprised of chemoheterotrophs and chemoautotrophs which derive nutrients from decomposition of organic material.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)Microbial Viability: Ability of a microbe to survive under given conditions. This can also be related to a colony's ability to replicate.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.Animal Feed: Foodstuff used especially for domestic and laboratory animals, or livestock.Cytophaga: A genus of gram-negative gliding bacteria found in SOIL; HUMUS; and FRESHWATER and marine habitats.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Blotting, Southern: A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.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.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Polyenes: Hydrocarbons with more than one double bond. They are a reduced form of POLYYNES.Research: Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.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.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Salmonella typhimurium: A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.Archaea: One of the three domains of life (the others being BACTERIA and Eukarya), formerly called Archaebacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: (1) the presence of characteristic tRNAs and ribosomal RNAs; (2) the absence of peptidoglycan cell walls; (3) the presence of ether-linked lipids built from branched-chain subunits; and (4) their occurrence in unusual habitats. While archaea resemble bacteria in morphology and genomic organization, they resemble eukarya in their method of genomic replication. The domain contains at least four kingdoms: CRENARCHAEOTA; EURYARCHAEOTA; NANOARCHAEOTA; and KORARCHAEOTA.Fungi: A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including MUSHROOMS; YEASTS; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies.Gram-Negative Bacterial Infections: Infections caused by bacteria that show up as pink (negative) when treated by the gram-staining method.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Zinc: A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.Antibiosis: A natural association between organisms that is detrimental to at least one of them. This often refers to the production of chemicals by one microorganism that is harmful to another.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Clostridium: A genus of motile or nonmotile gram-positive bacteria of the family Clostridiaceae. Many species have been identified with some being pathogenic. They occur in water, soil, and in the intestinal tract of humans and lower animals.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.Eubacterium: A genus of gram-positive, rod-shaped bacteria found in cavities of man and animals, animal and plant products, infections of soft tissue, and soil. Some species may be pathogenic. No endospores are produced. The genus Eubacterium should not be confused with EUBACTERIA, one of the three domains of life.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.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.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Intestines: The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.Actinobacteria: Class of BACTERIA with diverse morphological properties. Strains of Actinobacteria show greater than 80% 16S rDNA/rRNA sequence similarity among each other and also the presence of certain signature nucleotides. (Stackebrandt E. et al, Int. J. Syst. Bacteriol. (1997) 47:479-491)Mouth: The oval-shaped oral cavity located at the apex of the digestive tract and consisting of two parts: the vestibule and the oral cavity proper.Bacterial Outer Membrane Proteins: Proteins isolated from the outer membrane of Gram-negative bacteria.Genomic Library: A form of GENE LIBRARY containing the complete DNA sequences present in the genome of a given organism. It contrasts with a cDNA library which contains only sequences utilized in protein coding (lacking introns).Corynebacterium: A genus of asporogenous bacteria that is widely distributed in nature. Its organisms appear as straight to slightly curved rods and are known to be human and animal parasites and pathogens.Bacterial Load: Measurable quantity of bacteria in an object, organism, or organism compartment.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.Phagocytosis: The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).Food Microbiology: The presence of bacteria, viruses, and fungi in food and food products. This term is not restricted to pathogenic organisms: the presence of various non-pathogenic bacteria and fungi in cheeses and wines, for example, is included in this concept.Gastrointestinal Tract: Generally refers to the digestive structures stretching from the MOUTH to ANUS, but does not include the accessory glandular organs (LIVER; BILIARY TRACT; PANCREAS).Deltaproteobacteria: A group of PROTEOBACTERIA represented by morphologically diverse, anaerobic sulfidogens. Some members of this group are considered bacterial predators, having bacteriolytic properties.Gram-Negative Aerobic Rods and Cocci: A group of gram-negative bacteria consisting of rod- and coccus-shaped cells. They are both aerobic (able to grow under an air atmosphere) and microaerophilic (grow better in low concentrations of oxygen) under nitrogen-fixing conditions but, when supplied with a source of fixed nitrogen, they grow as aerobes.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.Bacteroidetes: A phylum of bacteria comprised of three classes: Bacteroides, Flavobacteria, and Sphingobacteria.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).Chlorobi: A phylum of anoxygenic, phototrophic bacteria including the family Chlorobiaceae. They occur in aquatic sediments, sulfur springs, and hot springs and utilize reduced sulfur compounds instead of oxygen.Air Microbiology: The presence of bacteria, viruses, and fungi in the air. This term is not restricted to pathogenic organisms.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)Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Glucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Fusobacterium: A genus of gram-negative, anaerobic, rod-shaped bacteria found in cavities of humans and other animals. No endospores are formed. Some species are pathogenic and occur in various purulent or gangrenous infections.Flavobacterium: A genus of gram-negative, aerobic, rod-shaped bacteria widely distributed in SOIL and WATER. Its organisms are also found in raw meats, MILK and other FOOD, hospital environments, and human clinical specimens. Some species are pathogenic in humans.Actinomycetales: An order of gram-positive, primarily aerobic BACTERIA that tend to form branching filaments.Sodium Chloride: A ubiquitous sodium salt that is commonly used to season food.Gram-Positive Cocci: Coccus-shaped bacteria that retain the crystal violet stain when treated by Gram's method.Environmental Microbiology: The study of microorganisms living in a variety of environments (air, soil, water, etc.) and their pathogenic relationship to other organisms including man.Metagenome: A collective genome representative of the many organisms, primarily microorganisms, existing in a community.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.Ecosystem: A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Salmonella: A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that utilizes citrate as a sole carbon source. It is pathogenic for humans, causing enteric fevers, gastroenteritis, and bacteremia. Food poisoning is the most common clinical manifestation. Organisms within this genus are separated on the basis of antigenic characteristics, sugar fermentation patterns, and bacteriophage susceptibility.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Sulfur: An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.Methane: The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)Anti-Infective Agents: Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.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.Pseudoalteromonas: A genus of GRAM-NEGATIVE AEROBIC BACTERIA of marine origin. Many species were formerly classified under ALTEROMONAS.Biodiversity: The variety of all native living organisms and their various forms and interrelationships.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Bacteroidaceae: A family of gram-negative bacteria found primarily in the intestinal tracts and mucous membranes of warm-blooded animals. Its organisms are sometimes pathogenic.Nitrogen Fixation: The process in certain BACTERIA; FUNGI; and CYANOBACTERIA converting free atmospheric NITROGEN to biologically usable forms of nitrogen, such as AMMONIA; NITRATES; and amino compounds.Waste Disposal, Fluid: The discarding or destroying of liquid waste products or their transformation into something useful or innocuous.Bifidobacterium: A rod-shaped, gram-positive, non-acid-fast, non-spore-forming, non-motile bacterium that is a genus of the family Bifidobacteriaceae, order Bifidobacteriales, class ACTINOBACTERIA. It inhabits the intestines and feces of humans as well as the human vagina.Marine Biology: The study of the origin, structure, development, growth, function, genetics, and reproduction of organisms which inhabit the OCEANS AND SEAS.Microscopy, Electron, Scanning: Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.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.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.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)Lipopolysaccharides: Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)Pseudomonas fluorescens: A species of nonpathogenic fluorescent bacteria found in feces, sewage, soil, and water, and which liquefy gelatin.Peptostreptococcus: A genus of gram-positive, anaerobic, coccoid bacteria that is part of the normal flora of humans. Its organisms are opportunistic pathogens causing bacteremias and soft tissue infections.Host-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.Gram-Negative Chemolithotrophic Bacteria: A large group of bacteria including those which oxidize ammonia or nitrite, metabolize sulfur and sulfur compounds, or deposit iron and/or manganese oxides.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)Enterobacter: Gram-negative gas-producing rods found in feces of humans and other animals, sewage, soil, water, and dairy products.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.
  • Pancreatic digest of casein used to supplement media in cultivation of anaerobic bacteria. (thomassci.com)
  • Metronidazole hydrochloride (Flagyl, Metric 21, Metro I.V., Protostat): used for anaerobic bacteria and protozoa. (encyclopedia.com)
  • Although the bacitracin sensitivities of mutants that had defects in flanking genes were similar to that of the parental strain Xc, mutants that were defective in mbrA , mbrB , mbrC , or mbrD were about 100 to 120 times more sensitive to bacitracin than strain Xc. (asm.org)
  • In addition, a mutant that was defective in all of the mbrABCD genes and rgpA was more sensitive to bacitracin than either the RGP or Mbr mutants. (asm.org)
  • In infants, bacitracin is rarely administered intramuscularly for the treatment of staphylococcal pneumonia and empyema when due to organisms shown susceptible to bacitracin. (wikipedia.org)
  • Its use should be restricted to infants with staphylococcal pneumonia and empyema when due to organisms shown to be susceptible to bacitracin. (nih.gov)
  • In accordance with the statements in the 'Warning Box', the use of intramuscular bacitracin is limited to the treatment of infants with pneumonia and empyema caused by staphylococci shown to be susceptible to the drug. (nih.gov)
  • Northern analysis demonstrated that bcrA , bcrB , and bcrD were transcribed as a polycistronic message that was induced by increasing concentrations of bacitracin but not by other cell wall-active antimicrobials (e.g., vancomycin). (asm.org)
  • Bacitracin is used widely in topical applications in human medicine, and its oral use for the control of vancomycin-resistant enterococci has been suggested ( 25 ). (asm.org)
  • The clinical use of bacitracin by oral administration is getting much attention for its ability to eradicate vancomycin-resistant enterococci (VRE) from the gastrointestinal tracts of patients ( 2 , 15 , 25 ). (asm.org)
  • γ-Secretase has recently been implicated in the endosomal penetration of L2/vDNA, but bacitracin had no effect on γ-secretase activity, indicating that blockage of this step occurs through a γ-secretase-independent mechanism. (asm.org)
  • 2004). For susceptibility testing two colonies of isolated bacteria inoculated in nutrient broth and incubated at 37C for 3 hours to become the turbidity of that as 0.5 McFarland (Baron and Finegold, 1990). (priory.com)