Acinetobacter Infections: Infections with bacteria of the genus ACINETOBACTER.Acinetobacter: A genus of gram-negative bacteria of the family MORAXELLACEAE, found in soil and water and of uncertain pathogenicity.Acinetobacter baumannii: A species of gram-negative, aerobic bacteria, commonly found in the clinical laboratory, and frequently resistant to common antibiotics.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).Acinetobacter calcoaceticus: A species of gram-negative, aerobic bacteria found in soil and water. Although considered to be normally nonpathogenic, this bacterium is a causative agent of nosocomial infections, particularly in debilitated individuals.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Cross Infection: Any infection which a patient contracts in a health-care institution.Carbapenems: A group of beta-lactam antibiotics in which the sulfur atom in the thiazolidine ring of the penicillin molecule is replaced by a carbon atom. THIENAMYCINS are a subgroup of carbapenems which have a sulfur atom as the first constituent of the side chain.Colistin: Cyclic polypeptide antibiotic from Bacillus colistinus. It is composed of Polymyxins E1 and E2 (or Colistins A, B, and C) which act as detergents on cell membranes. Colistin is less toxic than Polymyxin B, but otherwise similar; the methanesulfonate is used orally.Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).beta-Lactamases: Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.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.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.beta-Lactam Resistance: Nonsusceptibility of bacteria to the action of the beta-lactam antibiotics. Mechanisms responsible for beta-lactam resistance may be degradation of antibiotics by BETA-LACTAMASES, failure of antibiotics to penetrate, or low-affinity binding of antibiotics to targets.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).