Transferable beta-lactamase. A new mechanism for in vitro penicillin resistance in Streptococcus faecalis.
Although enterococci are relatively resistant to penicillin, the mechanism of resistance is largely unknown and enzymatic inactivation does not play a role. In this study, an isolate of Streptococcus faecalis was found to have beta lactamase activity resulting in complete inactivation of penicillin. With a high inoculum, this strain was resistant to greater than 1,000 micrograms/ml of penicillin. Penicillin resistance and beta lactamase activity were transferred by conjugation at a high frequency to an enterococcal laboratory recipient strain together with two plasmids of molecular size 34 X 10(6) and 56 X 10(6), thus demonstrating the emergence of plasmid-mediated penicillin resistance in the genus Streptococcus.
D013293:Enterococcus faecalis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D010403:Penicillin Resistance; D010405:Penicillinase / Q000096:biosynthesis / Q000378:metabolism*; D010406:Penicillins / Q000494:pharmacology*; D010957:Plasmids; D013290:Streptococcal Infections / Q000188:drug therapy / Q000209:etiology; D001618:beta-Lactamases / Q000378:metabolism*
D010406:Penicillins; D010405:Penicillinase; D001618:beta-Lactamases