{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T07:12:53Z","timestamp":1790233973752,"version":"4.1.0"},"reference-count":0,"publisher":"American Society for Microbiology","issue":"5","license":[{"start":{"date-parts":[[1986,11,1]],"date-time":"1986-11-01T00:00:00Z","timestamp":531187200000},"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":[[1986,11]]},"abstract":"<jats:p>Imipenem has excellent antimicrobial activity owing in part to beta-lactamase stability. We found that only 2 of over 350 Bacteroides fragilis group clinical isolates were resistant to imipenem, with an MIC of more than 16 micrograms\/ml. These two isolates from the Tufts Anaerobe Laboratory (TAL) were resistant to all other beta-lactam agents tested. The organisms were able to inactivate imipenem in broth cultures and contained similar beta-lactamases that were able to hydrolyze carbapenems, cephamycins, cephalosporins, and penicillins. The molecular sizes of the beta-lactamases in TAL2480 and TAL3636 were estimated to be 44,000 daltons. The novel beta-lactamase contained Zn2+ as a cofactor. An additional factor contributing to resistance was determined. The outer membranes of these two organisms were found to limit free diffusion of the drugs into the periplasm. This novel beta-lactamase, associated with a barrier to drug permeation, resulted in high-grade beta-lactam drug resistance.<\/jats:p>","DOI":"10.1128\/aac.30.5.645","type":"journal-article","created":{"date-parts":[[2012,6,28]],"date-time":"2012-06-28T00:04:52Z","timestamp":1340841892000},"page":"645-648","update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":131,"title":["Beta-lactamase-mediated imipenem resistance in Bacteroides fragilis"],"prefix":"10.1128","volume":"30","author":[{"suffix":"Jr","given":"G J","family":"Cuchural","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M H","family":"Malamy","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"F P","family":"Tally","sequence":"additional","affiliation":[],"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.30.5.645","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.30.5.645","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,21]],"date-time":"2022-02-21T14:57:46Z","timestamp":1645455466000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/AAC.30.5.645"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1986,11]]},"references-count":0,"journal-issue":{"issue":"5","published-print":{"date-parts":[[1986,11]]}},"alternative-id":["10.1128\/AAC.30.5.645"],"URL":"https:\/\/doi.org\/10.1128\/aac.30.5.645","relation":{},"ISSN":["0066-4804","1098-6596"],"issn-type":[{"value":"0066-4804","type":"print"},{"value":"1098-6596","type":"electronic"}],"subject":[],"published":{"date-parts":[[1986,11]]},"assertion":[{"value":"1986-11-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}