title: beta-Lactam susceptibility patterns and investigation of cephalosporin hydrolysing beta-lactamases of Gram-negative extraintestinal clinical isolates.
abstract: Of more than 3500 isolates of enterobacteriaceae, 48-69% were resistant to aminopenicillins and 11-45% to amoxycillin+clavulanic acid. Resistance to second and third generation cephalosporins was present in 11-17 and 3-8% of Escherichia coli, 47-56 and 15-52% of Klebsiella-Enterobacter, 36-57 and 16-27% of Proteus, Providencia and Morganella isolates. Pseudomonas aeruginosa strains varied in their resistance to antipseudomonal beta-lactams. Isoelectric points, inhibitor profiles and substrate profiles of beta-lactamases extracted from representatives of the resistant strains indicated that the resistance was mainly due to the hyperproduction of chromosomally encoded AmpC beta-lactamases. This was confirmed by plasmid profile and PCR investigations. Extended-spectrum beta-lactamase and metallo-penicillinase producing strains were not found. One Pseudomonas maltophilia strain produced an oxacillinase.
authors: Department of Pharmacology, University of Debrecen, Debrecen, Hungary.
authors: Z
authors: Z
authors: Gál
authors: D
authors: D
authors: Szabó
authors: P
authors: P
authors: Kovács
authors: F
authors: F
authors: Hernádi
authors: B
authors: B
authors: Tóth-Martinez
authors: F
authors: F
authors: Rozgonyi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002511:Cephalosporins / Q000378:metabolism*; D004352:Drug Resistance, Microbial; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D001618:beta-Lactamases