title: [Sensitivity of 5 beta-lactam antibiotics to beta-lactamase isolated from E. coli and its respective transconjugates].
abstract: 54 beta-lactamase producing E. coli were tested to observe their eventual capacity to transfer beta-lactamase production by conjugation to a receiving E. coli K12 C600 Na-. About 16% (9/54) of these strains transferred beta-lactamase producing capacity. MICs of five beta-lactam antibiotics (Ampicillin, Cephaloridine, Cephalexine, Cefuroxime, Cefotaxime) were performed against E. coli donors and E. coli K12 C600 transconjugates. It was observed a remarkable increase only of Ampicillin MICs against all transconjugates++. Beta-lactamases produced by donors and transconjugants were isolated and purified by sonication and high speed centrifugation. Sensitivity of the six antibiotics to these purified beta-lactamases was assessed by a spectrophotometric method that utilizes the velocity of cytochrome c reduction. beta-lactamases produced by transconjugants have identical substrate profile that beta-lactamases produced by donors.
mesh_terms: D000667:Ampicillin / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D002439:Cefotaxime / Q000378:metabolism; D002444:Cefuroxime / Q000378:metabolism; D002506:Cephalexin / Q000378:metabolism; D002509:Cephaloridine / Q000378:metabolism; D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D000667:Ampicillin; D001618:beta-Lactamases; D002509:Cephaloridine; D002439:Cefotaxime; D002444:Cefuroxime; D002506:Cephalexin
vernacular_title: Sensibilita' di 5 antibiotici beta-lattamici alle beta-lattamasi isolate da E. coli e dai rispettivi transconiuganti.