Transferable beta-lactamase. A new mechanism for in vitro penicillin resistance in Streptococcus faecalis.

B E Murray; B Mederski-Samaroj

doi:10.1172/JCI111042

Find articles by Murray, B. in: PubMed | Google Scholar

Find articles by Mederski-Samaroj, B. in: PubMed | Google Scholar

Published in Volume 72, Issue 3 on September 1, 1983
J Clin Invest. 1983;72(3):1168–1171. https://doi.org/10.1172/JCI111042.
© 1983 The American Society for Clinical Investigation

Published September 1, 1983 - Version history

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.

Images.

Click on an image below to see the page. View PDF of the complete article