{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,20]],"date-time":"2025-10-20T10:24:49Z","timestamp":1760955889935},"reference-count":0,"publisher":"American Society for Microbiology","issue":"2","license":[{"start":{"date-parts":[[1997,2,1]],"date-time":"1997-02-01T00:00:00Z","timestamp":854755200000},"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":[[1997,2]]},"abstract":"<jats:p>Ketolides, a novel macrolide subclass, possess a mode of action that is similar to that of structurally related macrolide-lincosamide-streptogramin (MLS) compounds. By using reference in vitro tests, the in vitro activity of RU-64004 was compared to those of six other MLS compounds against more than 800 clinical pathogens, including 356 gram-positive organisms. The spectrum of activity of the ketolide was most similar to that of clindamycin versus staphylococci and streptococci and superior to those of all macrolides tested against oxacillin-resistant staphylococci and vancomycin-resistant (vanA, vanB, and vanC) enterococcal isolates. The activity of the ketolide was greater than those of the macrolides, azalides, or clindamycin tested against vancomycin-susceptible enterococci (MICs at which 90% of isolates are inhibited [MIC90S], 0.25 to 4 micrograms\/ml), penicillin-resistant pneumococci (MIC90, 0.25 micrograms\/ml), and most beta-hemolytic streptococci. All Streptococcus pneumoniae and beta-hemolytic streptococcus strain were inhibited by ketolide concentrations of &lt; or = 0.25 micrograms\/ml. Against 165 erythromycin-resistant strains, RU-64004 inhibited (MICs, &lt; or = 0.5 micrograms\/ml) approximately one-third of staphylococci, all streptococci, and slightly more than one-half of the enterococci. Quinupristin-dalfopristin (a streptogramin combination) was active against all tested isolates with the exception of non-Enterococcus faecium enterococci, against which the ketolide exhibited greater potency (MIC50S, 0.03 to 2 micrograms\/ml). The ketolide was also active against Haemophilus influenzae (MIC90, 2 micrograms\/ml), Moraxella catarrhalis (MIC90, 0.12 micrograms\/ml), pathogenic Neisseria spp. (MIC90, 0.5 micrograms\/ml), and many gram-positive anaerobes (MIC90, 0.5 micrograms\/ml). RU-64004 may enhance the role of macrolide drugs in the treatment of some serious infections caused by MLS-resistant gram-positive organisms.<\/jats:p>","DOI":"10.1128\/aac.41.2.454","type":"journal-article","created":{"date-parts":[[2018,10,9]],"date-time":"2018-10-09T00:28:03Z","timestamp":1539044883000},"page":"454-459","update-policy":"http:\/\/dx.doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":46,"title":["In vitro evaluation of a novel ketolide antimicrobial agent, RU-64004"],"prefix":"10.1128","volume":"41","author":[{"given":"C","family":"Jamjian","sequence":"first","affiliation":[{"name":"Department of Pharmaceutical Care, University of Iowa Hospitals and Clinics, Iowa City 52242, USA."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D J","family":"Biedenbach","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Care, University of Iowa Hospitals and Clinics, Iowa City 52242, USA."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R N","family":"Jones","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Care, University of Iowa Hospitals and Clinics, Iowa City 52242, USA."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"235","container-title":["Antimicrobial Agents and Chemotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.41.2.454","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.41.2.454","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,21]],"date-time":"2022-02-21T20:12:37Z","timestamp":1645474357000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/AAC.41.2.454"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1997,2]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1997,2]]}},"alternative-id":["10.1128\/AAC.41.2.454"],"URL":"https:\/\/doi.org\/10.1128\/aac.41.2.454","relation":{},"ISSN":["0066-4804","1098-6596"],"issn-type":[{"value":"0066-4804","type":"print"},{"value":"1098-6596","type":"electronic"}],"subject":[],"published":{"date-parts":[[1997,2]]},"assertion":[{"value":"1997-02-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}