{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,26]],"date-time":"2025-10-26T14:29:05Z","timestamp":1761488945395},"reference-count":0,"publisher":"American Society for Microbiology","issue":"5","license":[{"start":{"date-parts":[[1994,5,1]],"date-time":"1994-05-01T00:00:00Z","timestamp":767750400000},"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":[[1994,5]]},"abstract":"<jats:p>The in vitro and in vivo antibacterial activities of the new rifamycin derivatives KRM-1648 and KRM-1657 were compared with those of rifampin. Rifabutin, ciprofloxacin, and clarithromycin were also tested for reference. The respective MICs of KRM-1648 and KRM-1657 for 90% of the strains tested (MIC90S) were 0.016 and 0.0078 microgram\/ml, respectively, for methicillin-susceptible Staphylococcus aureus, 0.016 and 0.0039 microgram\/ml, respectively, for methicillin-resistant S. aureus, and 0.0625 and 0.016 microgram\/ml, respectively, for methicillin- and quinolone-resistant S. aureus. These MIC90S of KRM-1657 were equal to or 2- to 64-fold lower than those of rifampin. KRM-1648 and KRM-1657 with MIC90S of between 0.002 and 0.078 microgram\/ml were 2- to 128-fold more active than rifampin against Staphylococcus epidermidis and Streptococcus species, including Streptococcus pneumoniae and Streptococcus pyogenes. The MIC90S of KRM-1657 for Haemophilus influenzae and Neisseria gonorrhoeae were 0.25 and 0.1 microgram\/ml, respectively; KRM-1657 was almost as active as rifampin and was 8- to 16-fold more active than KRM-1648 against these strains. The frequency of occurrence of spontaneous mutations to resistance to KRM-1648 and KRM-1657 was equal to that to rifampin. Against systemic infection with S. aureus in mice, the efficacies of KRM-1648 and KRM-1657 were comparable to that of rifampin.<\/jats:p>","DOI":"10.1128\/aac.38.5.1118","type":"journal-article","created":{"date-parts":[[2012,6,28]],"date-time":"2012-06-28T00:05:50Z","timestamp":1340841950000},"page":"1118-1122","update-policy":"http:\/\/dx.doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":33,"title":["In vitro and in vivo antibacterial activities of KRM-1648 and KRM-1657, new rifamycin derivatives"],"prefix":"10.1128","volume":"38","author":[{"given":"K","family":"Fujii","sequence":"first","affiliation":[{"name":"Department of Microbiology, Toho University School of Medicine, Tokyo, Japan."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A","family":"Tsuji","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Toho University School of Medicine, Tokyo, Japan."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S","family":"Miyazaki","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Toho University School of Medicine, Tokyo, Japan."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"K","family":"Yamaguchi","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Toho University School of Medicine, Tokyo, Japan."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S","family":"Goto","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Toho University School of Medicine, Tokyo, Japan."}],"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.38.5.1118","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.38.5.1118","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,21]],"date-time":"2022-02-21T15:38:40Z","timestamp":1645457920000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/AAC.38.5.1118"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,5]]},"references-count":0,"journal-issue":{"issue":"5","published-print":{"date-parts":[[1994,5]]}},"alternative-id":["10.1128\/AAC.38.5.1118"],"URL":"https:\/\/doi.org\/10.1128\/aac.38.5.1118","relation":{},"ISSN":["0066-4804","1098-6596"],"issn-type":[{"value":"0066-4804","type":"print"},{"value":"1098-6596","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,5]]},"assertion":[{"value":"1994-05-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}