Metronidazole: A nitroimidazole used to treat AMEBIASIS; VAGINITIS; TRICHOMONAS INFECTIONS; GIARDIASIS; ANAEROBIC BACTERIA; and TREPONEMAL INFECTIONS. It has also been proposed as a radiation sensitizer for hypoxic cells. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985, p133), this substance may reasonably be anticipated to be a carcinogen (Merck, 11th ed).Antitrichomonal Agents: Agents used to treat trichomonas infections.Nitroreductases: Enzymes which reduce nitro groups (NITRO COMPOUNDS) and other nitrogenous compounds.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).Amoxicillin: A broad-spectrum semisynthetic antibiotic similar to AMPICILLIN except that its resistance to gastric acid permits higher serum levels with oral administration.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Clarithromycin: A semisynthetic macrolide antibiotic derived from ERYTHROMYCIN that is active against a variety of microorganisms. It can inhibit PROTEIN SYNTHESIS in BACTERIA by reversibly binding to the 50S ribosomal subunits. This inhibits the translocation of aminoacyl transfer-RNA and prevents peptide chain elongation.Bismuth: A metallic element that has the atomic symbol Bi, atomic number 83 and atomic weight 208.98.NitroimidazolesHelicobacter 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.Trichomonas vaginalis: A species of TRICHOMONAS that produces a refractory vaginal discharge in females, as well as bladder and urethral infections in males.Bacteria, AnaerobicTinidazole: A nitroimidazole antitrichomonal agent effective against Trichomonas vaginalis, Entamoeba histolytica, and Giardia lamblia infections.Anti-Infective Agents: Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.Trichomonas Vaginitis: Inflammation of the vagina, marked by a purulent discharge. This disease is caused by the protozoan TRICHOMONAS VAGINALIS.Bacteroides fragilis: Gram-negative bacteria occurring in the lower intestinal tracts of man and other animals. It is the most common species of anaerobic bacteria isolated from human soft tissue infections.Anti-Ulcer Agents: Various agents with different action mechanisms used to treat or ameliorate PEPTIC ULCER or irritation of the gastrointestinal tract. This has included ANTIBIOTICS to treat HELICOBACTER INFECTIONS; HISTAMINE H2 ANTAGONISTS to reduce GASTRIC ACID secretion; and ANTACIDS for symptomatic relief.Clindamycin: An antibacterial agent that is a semisynthetic analog of LINCOMYCIN.Bacteroides Infections: Infections with bacteria of the genus BACTEROIDES.Omeprazole: A 4-methoxy-3,5-dimethylpyridyl, 5-methoxybenzimidazole derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits an H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS.Enterocolitis, Pseudomembranous: An acute inflammation of the INTESTINAL MUCOSA that is characterized by the presence of pseudomembranes or plaques in the SMALL INTESTINE (pseudomembranous enteritis) and the LARGE INTESTINE (pseudomembranous colitis). It is commonly associated with antibiotic therapy and CLOSTRIDIUM DIFFICILE colonization.Vaginosis, Bacterial: Polymicrobial, nonspecific vaginitis associated with positive cultures of Gardnerella vaginalis and other anaerobic organisms and a decrease in lactobacilli. It remains unclear whether the initial pathogenic event is caused by the growth of anaerobes or a primary decrease in lactobacilli.Ornidazole: A nitroimidazole antiprotozoal agent used in ameba and trichomonas infections. It is partially plasma-bound and also has radiation-sensitizing action.Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).Tetracycline: A naphthacene antibiotic that inhibits AMINO ACYL TRNA binding during protein synthesis.Clostridium difficile: A common inhabitant of the colon flora in human infants and sometimes in adults. It produces a toxin that causes pseudomembranous enterocolitis (ENTEROCOLITIS, PSEUDOMEMBRANOUS) in patients receiving antibiotic therapy.Antiprotozoal Agents: Substances that are destructive to protozoans.Drug Therapy, Combination: Therapy with two or more separate preparations given for a combined effect.Tritrichomonas: A genus of flagellate EUKARYOTES possessing three long anterior flagella.Nimorazole: An antitrichomonal agent which is effective either topically or orally and whose urinary metabolites are also trichomonicidal.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).Amebicides: Agents which are destructive to amebae, especially the parasitic species causing AMEBIASIS in man and animal.NitrofuransFurazolidone: A nitrofuran derivative with antiprotozoal and antibacterial activity. Furazolidone acts by gradual inhibition of monoamine oxidase. (From Martindale, The Extra Pharmacopoeia, 30th ed, p514)Rosacea: A cutaneous disorder primarily of convexities of the central part of the FACE, such as FOREHEAD; CHEEK; NOSE; and CHIN. It is characterized by FLUSHING; ERYTHEMA; EDEMA; RHINOPHYMA; papules; and ocular symptoms. It may occur at any age but typically after age 30. There are various subtypes of rosacea: erythematotelangiectatic, papulopustular, phymatous, and ocular (National Rosacea Society's Expert Committee on the Classification and Staging of Rosacea, J Am Acad Dermatol 2002; 46:584-7).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.Gardnerella vaginalis: A species in the genus GARDNERELLA previously classified as Haemophilus vaginalis. This bacterium, also isolated from the female genital tract of healthy women, is implicated in the cause of bacterial vaginosis (VAGINOSIS, BACTERIAL).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).Ranitidine: A non-imidazole blocker of those histamine receptors that mediate gastric secretion (H2 receptors). It is used to treat gastrointestinal ulcers.Giardia lamblia: A species of parasitic EUKARYOTES that attaches itself to the intestinal mucosa and feeds on mucous secretions. The organism is roughly pear-shaped and motility is somewhat erratic, with a slow oscillation about the long axis.Pyruvate Synthase: A ferredoxin-containing enzyme that catalyzes the COENZYME A-dependent oxidative decarboxylation of PYRUVATE to acetyl-COENZYME A and CARBON DIOXIDE.Suppositories: Medicated dosage forms that are designed to be inserted into the rectal, vaginal, or urethral orifice of the body for absorption. Generally, the active ingredients are packaged in dosage forms containing fatty bases such as cocoa butter, hydrogenated oil, or glycerogelatin that are solid at room temperature but melt or dissolve at body temperature.Trichomonas: A genus of parasitic flagellate EUKARYOTES distinguished by the presence of four anterior flagella, an undulating membrane, and a trailing flagellum.Bacteria, AerobicGiardiasis: An infection of the SMALL INTESTINE caused by the flagellated protozoan GIARDIA LAMBLIA. It is spread via contaminated food and water and by direct person-to-person contact.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.Duodenal Ulcer: A PEPTIC ULCER located in the DUODENUM.Niridazole: An antischistosomal agent that has become obsolete.Entamoeba histolytica: A species of parasitic protozoa causing ENTAMOEBIASIS and amebic dysentery (DYSENTERY, AMEBIC). Characteristics include a single nucleus containing a small central karyosome and peripheral chromatin that is finely and regularly beaded.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)Peptic Ulcer: Ulcer that occurs in the regions of the GASTROINTESTINAL TRACT which come into contact with GASTRIC JUICE containing PEPSIN and GASTRIC ACID. It occurs when there are defects in the MUCOSA barrier. The common forms of peptic ulcers are associated with HELICOBACTER PYLORI and the consumption of nonsteroidal anti-inflammatory drugs (NSAIDS).Organometallic Compounds: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)2-Pyridinylmethylsulfinylbenzimidazoles: Compounds that contain benzimidazole joined to a 2-methylpyridine via a sulfoxide linkage. Several of the compounds in this class are ANTI-ULCER AGENTS that act by inhibiting the POTASSIUM HYDROGEN ATPASE found in the PROTON PUMP of GASTRIC PARIETAL CELLS.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)Nifuratel: Local antiprotozoal and antifungal agent that may also be given orally.Premedication: Preliminary administration of a drug preceding a diagnostic, therapeutic, or surgical procedure. The commonest types of premedication are antibiotics (ANTIBIOTIC PROPHYLAXIS) and anti-anxiety agents. It does not include PREANESTHETIC MEDICATION.Trichomonas Infections: Infections in birds and mammals produced by various species of Trichomonas.Administration, Oral: The giving of drugs, chemicals, or other substances by mouth.Blastocystis hominis: A species of parasitic protozoa found in the intestines of humans and other primates. It was classified as a yeast in 1912. Over the years, questions arose about this designation. In 1967, many physiological and morphological B. hominis characteristics were reported that fit a protozoan classification. Since that time, other papers have corroborated this work and the organism is now recognized as a protozoan parasite of humans causing intestinal disease with potentially disabling symptoms.Cefoxitin: A semisynthetic cephamycin antibiotic resistant to beta-lactamase.Antacids: Substances that counteract or neutralize acidity of the GASTROINTESTINAL TRACT.Bacterial Infections: Infections by bacteria, general or unspecified.Ribotyping: RESTRICTION FRAGMENT LENGTH POLYMORPHISM analysis of rRNA genes that is used for differentiating between species or strains.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.Drug Resistance: Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.Liver Abscess, Amebic: Single or multiple areas of PUS due to infection by any ameboid protozoa (AMEBIASIS). A common form is caused by the ingestion of ENTAMOEBA HISTOLYTICA.BulgariaIodoquinol: One of the halogenated 8-quinolinols widely used as an intestinal antiseptic, especially as an antiamebic agent. It is also used topically in other infections and may cause CNS and eye damage. It is known by very many similar trade names world-wide.Dyspepsia: Impaired digestion, especially after eating.Lansoprazole: A 2,2,2-trifluoroethoxypyridyl derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS. Lansoprazole is a racemic mixture of (R)- and (S)-isomers.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.Administration, Intravaginal: The insertion of drugs into the vagina to treat local infections, neoplasms, or to induce labor. The dosage forms may include medicated pessaries, irrigation fluids, and suppositories.Fusobacterium Infections: Infections with bacteria of the genus FUSOBACTERIUM.