{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T12:29:39Z","timestamp":1791894579210,"version":"4.3.4"},"reference-count":0,"publisher":"American Society for Microbiology","issue":"10","license":[{"start":{"date-parts":[[1991,10,1]],"date-time":"1991-10-01T00:00:00Z","timestamp":686275200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Antimicrob Agents Chemother"],"published-print":{"date-parts":[[1991,10]]},"abstract":"<jats:p>Staphylococcus aureus strains bearing the 17.2-kb beta-lactamase plasmid pBW15 and belonging to phage group 94\/96 exhibit borderline susceptibility to the antistaphylococcal penicillins. Borderline susceptibility within phage group 94\/96 is thought to be mediated by the hyperproduction of type A staphylococcal beta-lactamase. Evaluation of 84 non-94\/96 phage type S. aureus strains that also produced the type A enzyme identified 7 additional hyperproducing strains. However, none of these isolates contained pBW15, and only one met the criteria for borderline susceptibility. To determine the role of pBW15 and the 94\/96 phage type in the expression of borderline susceptibility, pBW15 was transformed in two plasmid-free, penicillin-susceptible strains, one of which belonged to phage group 94\/96. Penicillin MICs for both transformants and quantitative beta-lactamase activity were comparable to those for the parent pBW15-containing strain. A fourfold difference in the oxacillin MICs for the 94\/96 and non-94\/96 phage type transformants (1.0 and 0.25 microgram\/ml, respectively) was identified, and only the 94\/96 phage type transformant met the criteria for borderline susceptibility. Chromosomal DNA from borderline-susceptible phage group 94\/96 strains did not hybridize with a probe for mecA, and the beta-lactam binding affinity of PBPs 1, 2, 3, and 4 from a penicillin-susceptible 94\/96 phage type strain and a non-94\/96 phage type strain were comparable. Although hyperproduction of the type A beta-lactamase appears to be necessary for the expression of borderline susceptibility within certain phage group 94\/96 strains, beta-lactamase production of a comparable magnitude by a group of S. aureus strains belonging to other phage types does not confer borderline susceptibility. These data suggest that borderline susceptibility is not solely due to the hyperproduction of beta-lactamase.<\/jats:p>","DOI":"10.1128\/aac.35.10.1975","type":"journal-article","created":{"date-parts":[[2012,6,28]],"date-time":"2012-06-28T00:05:50Z","timestamp":1340841950000},"page":"1975-1979","update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":52,"title":["Borderline susceptibility to antistaphylococcal penicillins is not conferred exclusively by the hyperproduction of beta-lactamase"],"prefix":"10.1128","volume":"35","author":[{"given":"N","family":"Barg","sequence":"first","affiliation":[{"name":"Department of Medicine, Vanderbilt University Medical School, Nashville, Tennessee 37202."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H","family":"Chambers","sequence":"additional","affiliation":[{"name":"Department of Medicine, Vanderbilt University Medical School, Nashville, Tennessee 37202."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D","family":"Kernodle","sequence":"additional","affiliation":[{"name":"Department of Medicine, Vanderbilt University Medical School, Nashville, Tennessee 37202."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","container-title":["Antimicrobial Agents and Chemotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.35.10.1975","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.35.10.1975","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,21]],"date-time":"2022-02-21T15:14:43Z","timestamp":1645456483000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/AAC.35.10.1975"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1991,10]]},"references-count":0,"journal-issue":{"issue":"10","published-print":{"date-parts":[[1991,10]]}},"alternative-id":["10.1128\/AAC.35.10.1975"],"URL":"https:\/\/doi.org\/10.1128\/aac.35.10.1975","relation":{},"ISSN":["0066-4804","1098-6596"],"issn-type":[{"value":"0066-4804","type":"print"},{"value":"1098-6596","type":"electronic"}],"subject":[],"published":{"date-parts":[[1991,10]]},"assertion":[{"value":"1991-10-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}