title: Beta-lactamases in anaerobic bacteria.
abstract: The known mechanisms of beta-lactam resistance in anaerobic bacteria involve production of beta-lactamases, alteration of penicillin-binding proteins and blocked penetration of beta-lactams through the outer membranes. The most important factor in beta-lactam resistance is production of beta-lactamase. Beta-lactamases in various Bacteroides, Fusobacterium and Clostridium species have been described. Beta-lactam resistance in Bacteroides fragilis is most commonly mediated by beta-lactamase production mainly of cephalosporinase character. Recent studies have also shown that B. fragilis can produce a penicillinase which inactivates piperacillin and carbenicillin. Enzymes inactivating cefoxitin and imipenem have also been isolated from B. fragilis. The Bacteroides non-fragilis species produce beta-lactamases of mainly penicillinase character. Recently a penicillinase from Fusobacterium nucleatum has been characterized. Among the clostridia, Clostridium butyricum, C. clostridiiformis and C. ramosum have been shown to produce penicillinases.
mesh_terms: D001421:Bacteria, Anaerobic / Q000201:enzymology*; D001439:Bacteroides / Q000201:enzymology; D001441:Bacteroides fragilis / Q000201:enzymology; D002510:Cephalosporinase / Q000378:metabolism; D003013:Clostridium / Q000201:enzymology; D004352:Drug Resistance, Microbial; D004790:Enzyme Induction; D005673:Fusobacterium / Q000201:enzymology; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010405:Penicillinase / Q000378:metabolism; D013379:Substrate Specificity; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D065093:beta-Lactamase Inhibitors; D002510:Cephalosporinase; D010405:Penicillinase; D001618:beta-Lactamases