title: Plasmid-determined beta-lactamases identified in a group of 204 ampicillin-resistant Enterobacteriaceae.
abstract: Information is presented on the plasmid-determined beta-lactamases identified in 204 strains of ampicillin-resistant Enterobacteriaceae. The type most frequently identified was TEM-1 (in 85.3% of the strains), followed by SHV-1 (14.70%). Two types of plasmid-determined beta-lactamase were identified in 20 strains; in 18 of them one of the two was TEM-1 and in 13, SHV-1 (the TEM-1 + SHV-1 combination was observed in 12 strains). In the 41 Klebsiella strains the most frequently identified enzyme was SHV-1 (in 28 of the strains) and the proportion of strains with two plasmid-determined beta-lactamases was higher than in the other species studied.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology*; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D010403:Penicillin Resistance; D010957:Plasmids; D001618:beta-Lactamases / Q000032:analysis* / Q000235:genetics
chemical_list: D000667:Ampicillin; D001618:beta-Lactamases