[Mechanisms of bacterial resistance to beta-lactams by beta-lactamases].
The beta-lactamases are bacterial enzymes that inactivate beta-lactam antibiotics by catalyzing the hydrolysis of the amide group of the beta-lactam ring. They are the source of much bacterial resistance to those antibiotics. Structural studies on the enzymes, i.e., penicillinases and cephalosporinases, are now well-advanced and the up-to-date knowledge of this research field were explained together with the proposed mechanism of beta-lactam hydrolysis by a cephalosporinase. After the introduction of the beta-lactamase-stable beta-lactams such as oxyimino cephalosporins, R plasmid-mediated penicillinases and a chromosomal cephalosporinase have been found to be adapted to the new drugs by mutation. The characteristics of the mutant beta-lactamases and their importance in the bacterial resistance to the new beta-lactams were explained.
Sawai
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Division of Microbial Chemistry, Faculty of Pharmaceutical Sciences, Chiba University.
D000900:Anti-Bacterial Agents / Q000378:metabolism; D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D006868:Hydrolysis; D015394:Molecular Structure; D009154:Mutation; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000737:chemistry / Q000235:genetics; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases