{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T11:42:51Z","timestamp":1791286971746,"version":"4.1.0"},"reference-count":21,"publisher":"S. Karger AG","issue":"1","license":[{"start":{"date-parts":[[2012,1,1]],"date-time":"2012-01-01T00:00:00Z","timestamp":1325376000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"},{"start":{"date-parts":[[2012,1,1]],"date-time":"2012-01-01T00:00:00Z","timestamp":1325376000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chemotherapy"],"published-print":{"date-parts":[[2012]]},"abstract":"<i>Background:<\/i> Fluoroquinolone-resistant and extended-spectrum \u03b2-lactamase (ESBL)-carrying multidrug-resistant <i>Escherichia coli<\/i> have become severely problematic. In particular, a lineage of multilocus sequence-type ST131 which belongs to O25:H4 and carries ESBL CTX-M-15 has spread worldwide. <i>Methods:<\/i> Fluoroquinolone-resistant <i>E. coli <\/i>strains were isolated from various clinical specimens in a commercial clinical laboratory in 2008 and 2009 in Hokkaido Prefecture, Japan. <i>Results:<\/i> Among 478 clinical isolates, 112 strains (23.4%) showed levofloxacin (LVX) resistance. About 80% of the fluoroquinolone-resistant strains (88 strains) showed common features, namely O25:H4-ST131, phylogenetic group B and the same mutation pattern in quinolone resistance-determining regions. Pulsed field gel electrophoresis patterns suggested numerous lineages of O25:H4-ST131. The fluoroquinolone-resistant strains, including strains of O25:H4-ST131 and other types, more frequently shared CTX-type ESBL genes than did fluoroquinolone-susceptible strains. The ESBL genes fell into the CTX-M-9 and CTX-M-2 groups. CTX-M-15 (CTX-M-1 group) was not found among any of the strains isolated in this study. Sitafloxacin showed markedly potent activity against<i> E. coli<\/i> isolates compared with LVX, ciprofloxacin and ulifloxacin. <i>Conclusion:<\/i> The most prevalent fluoroquinolone-resistant strains of <i>E. coli<\/i> isolated in Hokkaido Prefecture, Japan, are O25:H4-ST131. However, similar to other areas of Japan, the ST131 clones represent distinct lineages from the general worldwide dispersal of multidrug-resistant clones which carry CTX-M-15.<\/jats:p>","DOI":"10.1159\/000336129","type":"journal-article","created":{"date-parts":[[2012,2,15]],"date-time":"2012-02-15T10:09:22Z","timestamp":1329300562000},"page":"52-59","source":"Crossref","is-referenced-by-count":27,"title":["Prevalence of Fluoroquinolone-Resistant <i>Escherichia coli<\/i> O25:H4-ST131 (CTX-M-15-Nonproducing) Strains Isolated in Japan"],"prefix":"10.1159","volume":"58","author":[{"given":"Shin-ichi","family":"Yokota","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Toyotaka","family":"Sato","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Torahiko","family":"Okubo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasuo","family":"Ohkoshi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tamaki","family":"Okabayashi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Osamu","family":"Kuwahara","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yutaka","family":"Tamura","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nobuhiro","family":"Fujii","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"127","published-online":{"date-parts":[[2012,2,15]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.1016%2FS1473-3099%2808%2970041-0"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1159%2F000290972"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1159%2F000329661"},{"key":"ref4","doi-asserted-by":"publisher","DOI":"10.1016%2Fj.ijantimicag.2009.11.003"},{"key":"ref5","doi-asserted-by":"publisher","DOI":"10.1086%2F653932"},{"key":"ref6","doi-asserted-by":"publisher","DOI":"10.1093%2Fjac%2Fdkm464"},{"key":"ref7","doi-asserted-by":"publisher","DOI":"10.3201%2Feid1402.070350"},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.1016%2Fj.pupt.2005.09.009"},{"key":"ref9","doi-asserted-by":"publisher","DOI":"10.1128%2FJCM.42.8.3483-3489.2004"},{"key":"ref10","doi-asserted-by":"publisher","DOI":"10.1128%2FJCM.01093-07"},{"key":"ref11","doi-asserted-by":"publisher","DOI":"10.1128%2FJCM.02070-06"},{"key":"ref12","doi-asserted-by":"publisher","DOI":"10.1128%2FJCM.01740-08"},{"key":"ref13","doi-asserted-by":"publisher","DOI":"10.1128%2FAEM.66.10.4555-4558.2000"},{"key":"ref14","doi-asserted-by":"publisher","DOI":"10.1111%2Fj.1442-2042.2006.01398.x"},{"key":"ref15","doi-asserted-by":"publisher","DOI":"10.1128%2FAAC.50.2.791-795.2006"},{"key":"ref16","doi-asserted-by":"publisher","DOI":"10.1093%2Fjac%2Fdkn463"},{"key":"ref17","doi-asserted-by":"publisher","DOI":"10.1128%2FJCM.43.12.5860-5864.2005"},{"key":"ref18","doi-asserted-by":"publisher","DOI":"10.1111%2Fj.1365-2958.2006.05172.x"},{"key":"ref19","doi-asserted-by":"publisher","DOI":"10.1093%2Fjac%2Fdkn084"},{"key":"ref20","doi-asserted-by":"publisher","DOI":"10.1186%2F1471-2180-5-4"},{"key":"ref21","doi-asserted-by":"publisher","DOI":"10.1128%2FJCM.01488-07"}],"container-title":["Chemotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/336129","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/336129","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/336129","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T19:04:47Z","timestamp":1745435087000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000336129"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012]]},"references-count":21,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2012,3,1]]},"published-print":{"date-parts":[[2012,3,12]]}},"URL":"https:\/\/doi.org\/10.1159\/000336129","archive":["Portico"],"relation":{},"ISSN":["0009-3157","1421-9794"],"issn-type":[{"value":"0009-3157","type":"print"},{"value":"1421-9794","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012]]}}}