title: Nosocomial infection and its molecular mechanisms of antibiotic resistance.
abstract: Nosocomial infection is a kind of infection, which is spread in various hospital environments, and leads to many serious diseases (e.g. pneumonia, urinary tract infection, gastroenteritis, and puerperal fever), and causes higher mortality than community-acquired infection. Bacteria are predominant among all the nosocomial infection-associated pathogens, thus a large number of antibiotics, such as aminoglycosides, penicillins, cephalosporins, and carbapenems, are adopted in clinical treatment. However, in recent years antibiotic resistance quickly spreads worldwide and causes a critical threat to public health. The predominant bacteria include Methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii. In these bacteria, resistance emerged from antibiotic resistant genes and many of those can be exchanged between bacteria. With technical advances, molecular mechanisms of resistance have been gradually unveiled. In this review, recent advances in knowledge about mechanisms by which (i) bacteria hydrolyze antibiotics (e.g. extended spectrum β-lactamases, (ii) AmpC β-lactamases, carbapenemases), (iii) avoid antibiotic targeting (e.g. mutated vanA and mecA genes), (iv) prevent antibiotic permeation (e.g. porin deficiency), or (v) excrete intracellular antibiotics (e.g. active efflux pump) are summarized.
authors.affiliation: Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo.
authors.forename: Jufeng
authors.initials: J
authors.lastname: Xia
authors.forename: Jianjun
authors.initials: J
authors.lastname: Gao
authors.forename: Wei
authors.initials: W
authors.lastname: Tang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism; D003428:Cross Infection / Q000188:drug therapy* / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000187:drug effects / Q000235:genetics; D006801:Humans; D006868:Hydrolysis; D009154:Mutation / Q000235:genetics; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases