Prevalence and distribution of R plasmid mediated beta-lactamases in Enterobacteriaceae.

290 ampicillin - resistant clinical isolates of various genera of Enterobacteriaceae were collected. 223 our of 290 isolates produced beta-lactamases: 95 of these resulted R plasmid mediated. The predominant R plasmid beta-lactamase was the TEM-1 enzyme. TEM-2 and SHV-1 enzymes were also produced.