Rifampin: A semisynthetic antibiotic produced from Streptomyces mediterranei. It has a broad antibacterial spectrum, including activity against several forms of Mycobacterium. In susceptible organisms it inhibits DNA-dependent RNA polymerase activity by forming a stable complex with the enzyme. It thus suppresses the initiation of RNA synthesis. Rifampin is bactericidal, and acts on both intracellular and extracellular organisms. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1160)Antibiotics, Antitubercular: Substances obtained from various species of microorganisms that are, alone or in combination with other agents, of use in treating various forms of tuberculosis; most of these agents are merely bacteriostatic, induce resistance in the organisms, and may be toxic.Isoniazid: Antibacterial agent used primarily as a tuberculostatic. It remains the treatment of choice for tuberculosis.Pyrazinamide: A pyrazine that is used therapeutically as an antitubercular agent.Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).Ethambutol: An antitubercular agent that inhibits the transfer of mycolic acids into the cell wall of the tubercle bacillus. It may also inhibit the synthesis of spermidine in mycobacteria. The action is usually bactericidal, and the drug can penetrate human cell membranes to exert its lethal effect. (From Smith and Reynard, Textbook of Pharmacology, 1992, p863)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.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Rifamycins: A group of ANTI-BACTERIAL AGENTS characterized by a chromophoric naphthohydroquinone group spanned by an aliphatic bridge not previously found in other known ANTI-BACTERIAL AGENTS. They have been isolated from fermentation broths of Streptomyces mediterranei.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).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).Streptomycin: An antibiotic produced by the soil actinomycete Streptomyces griseus. It acts by inhibiting the initiation and elongation processes during protein synthesis.Tuberculosis, Multidrug-Resistant: Tuberculosis resistant to chemotherapy with two or more ANTITUBERCULAR AGENTS, including at least ISONIAZID and RIFAMPICIN. The problem of resistance is particularly troublesome in tuberculous OPPORTUNISTIC INFECTIONS associated with HIV INFECTIONS. It requires the use of second line drugs which are more toxic than the first line regimens. TB with isolates that have developed further resistance to at least three of the six classes of second line drugs is defined as EXTENSIVELY DRUG-RESISTANT TUBERCULOSIS.Rifabutin: A broad-spectrum antibiotic that is being used as prophylaxis against disseminated Mycobacterium avium complex infection in HIV-positive patients.Tuberculosis, Pulmonary: MYCOBACTERIUM infections of the lung.Tuberculosis: Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.DNA-Directed RNA Polymerases: Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).Drug Interactions: The action of a drug that may affect the activity, metabolism, or toxicity of another drug.Ofloxacin: A synthetic fluoroquinolone antibacterial agent that inhibits the supercoiling activity of bacterial DNA GYRASE, halting DNA REPLICATION.Leprostatic Agents: Substances that suppress Mycobacterium leprae, ameliorate the clinical manifestations of leprosy, and/or reduce the incidence and severity of leprous reactions.Chloramphenicol: An antibiotic first isolated from cultures of Streptomyces venequelae in 1947 but now produced synthetically. It has a relatively simple structure and was the first broad-spectrum antibiotic to be discovered. It acts by interfering with bacterial protein synthesis and is mainly bacteriostatic. (From Martindale, The Extra Pharmacopoeia, 29th ed, p106)Staphylococcal Infections: Infections with bacteria of the genus STAPHYLOCOCCUS.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.Clofazimine: A fat-soluble riminophenazine dye used for the treatment of leprosy. It has been used investigationally in combination with other antimycobacterial drugs to treat Mycobacterium avium infections in AIDS patients. Clofazimine also has a marked anti-inflammatory effect and is given to control the leprosy reaction, erythema nodosum leprosum. (From AMA Drug Evaluations Annual, 1993, p1619)Diarylquinolines: A class of quinoline compounds defined by the presence of two aromatic ring structures which are attached via a side chain to carbon 3 of the qunolinyl structure. The two aromatic moieties are typically NAPTHALENE and BENZENE. Several compounds in this class are used as ANTITUBERCULAR AGENTS.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.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.Aza CompoundsDaptomycin: A cyclic lipopeptide antibiotic that inhibits GRAM-POSITIVE BACTERIA.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Ciprofloxacin: A broad-spectrum antimicrobial carboxyfluoroquinoline.Drug Synergism: The action of a drug in promoting or enhancing the effectiveness of another drug.Bacterial Proteins: Proteins found in any species of bacterium.Trimethoprim: A pyrimidine inhibitor of dihydrofolate reductase, it is an antibacterial related to PYRIMETHAMINE. It is potentiated by SULFONAMIDES and the TRIMETHOPRIM, SULFAMETHOXAZOLE DRUG COMBINATION is the form most often used. It is sometimes used alone as an antimalarial. TRIMETHOPRIM RESISTANCE has been reported.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.Anti-Infective Agents: Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.Oxazolidinones: Derivatives of oxazolidin-2-one. They represent an important class of synthetic antibiotic agents.Sputum: Material coughed up from the lungs and expectorated via the mouth. It contains MUCUS, cellular debris, and microorganisms. It may also contain blood or pus.Acetamides: Derivatives of acetamide that are used as solvents, as mild irritants, and in organic synthesis.Drug Resistance, Multiple, Bacterial: The ability of bacteria to resist or to become tolerant to several structurally and functionally distinct drugs simultaneously. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).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.Mycobacteriophages: Viruses whose host is one or more Mycobacterium species. They include both temperate and virulent types.Mycobacterium: A genus of gram-positive, aerobic bacteria. Most species are free-living in soil and water, but the major habitat for some is the diseased tissue of warm-blooded hosts.