{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T01:54:11Z","timestamp":1791251651621,"version":"4.1.0"},"reference-count":15,"publisher":"Cambridge University Press (CUP)","issue":"1","license":[{"start":{"date-parts":[[2009,6,29]],"date-time":"2009-06-29T00:00:00Z","timestamp":1246233600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Epidemiol. Infect."],"published-print":{"date-parts":[[2010,1]]},"abstract":"<jats:title>SUMMARY<\/jats:title><jats:p>In South Africa, for the years 2003\u20132007, the Enteric Diseases Reference Unit received 510 human isolates of <jats:italic>Salmonella<\/jats:italic> Typhi, of which 27 were nalidixic acid-resistant [minimum inhibitory concentrations (MICs) 128\u2013512 \u03bcg\/ml] with reduced susceptibility to ciprofloxacin (MICs 0\u00b7125\u20130\u00b75 \u03bcg\/ml). Pulsed-field gel electrophoresis analysis of 19 available isolates differentiated them into five DNA pattern types; multiple-locus variable-number tandem repeat analysis differentiated the isolates into 10 types. This level of genetic diversity suggested that resistant strains usually emerged independently of one another. A 16- to 32-fold decrease in nalidixic acid MIC and a 2- to 8-fold decrease in ciprofloxacin MIC, was observed in the presence of an efflux pump inhibitor. All isolates were negative by PCR screening for <jats:italic>qnr<\/jats:italic> genes. Seven resistant isolates were further analysed for mutations in the quinolone resistance-determining region of <jats:italic>gyrA<\/jats:italic>, <jats:italic>gyrB<\/jats:italic>, <jats:italic>parC<\/jats:italic> and <jats:italic>parE<\/jats:italic>. No amino-acid mutations were identified in GyrB and ParE; all isolates showed amino-acid mutations in both GyrA and ParC. We conclude that amino-acid mutations in GyrA and ParC in combination with active efflux of antibiotic out of the bacterial cell are the probable mechanisms conferring quinolone resistance.<\/jats:p>","DOI":"10.1017\/s0950268809990331","type":"journal-article","created":{"date-parts":[[2009,6,29]],"date-time":"2009-06-29T10:59:14Z","timestamp":1246273154000},"page":"86-90","source":"Crossref","is-referenced-by-count":33,"title":["Quinolone-resistant <i>Salmonella<\/i> Typhi in South Africa, 2003\u20132007"],"prefix":"10.1017","volume":"138","author":[{"given":"A. M.","family":"SMITH","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"N.","family":"GOVENDER","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K. H.","family":"KEDDY","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2009,6,29]]},"reference":[{"key":"S0950268809990331_ref014","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.47.11.3567-3573.2003"},{"key":"S0950268809990331_ref009","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.48.10.4012-4015.2004"},{"key":"S0950268809990331_ref006","doi-asserted-by":"publisher","DOI":"10.4103\/0255-0857.37369"},{"key":"S0950268809990331_ref003","doi-asserted-by":"publisher","DOI":"10.1086\/428052"},{"key":"S0950268809990331_ref001","first-page":"346","article-title":"The global burden of typhoid fever","volume":"82","author":"Crump","year":"2004","journal-title":"Bulletin of the World Health Organisation"},{"key":"S0950268809990331_ref004","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.47.2.559-562.2003"},{"key":"S0950268809990331_ref011","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dkm081"},{"key":"S0950268809990331_ref002","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.47.2.827-829.2003"},{"key":"S0950268809990331_ref013","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.48.10.3729-3735.2004"},{"key":"S0950268809990331_ref008","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.41.9.4388-4394.2003"},{"key":"S0950268809990331_ref005","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.42.4.1477-1482.2004"},{"key":"S0950268809990331_ref007","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2334-5-49"},{"key":"S0950268809990331_ref015","doi-asserted-by":"crossref","first-page":"1009","DOI":"10.1128\/AAC.40.4.1009","article-title":"Mutations in gyrA gene of quinolone-resistant Salmonella serotypes isolated from humans and animals","volume":"40","author":"Griggs","year":"1996","journal-title":"Antimicrobial Agents and Chemotherapy"},{"key":"S0950268809990331_ref012","doi-asserted-by":"publisher","DOI":"10.1089\/10766290260469543"},{"key":"S0950268809990331_ref010","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.50.4.1178-1182.2006"}],"container-title":["Epidemiology and Infection"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0950268809990331","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,4,28]],"date-time":"2019-04-28T17:13:12Z","timestamp":1556471592000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0950268809990331\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,6,29]]},"references-count":15,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2010,1]]}},"alternative-id":["S0950268809990331"],"URL":"https:\/\/doi.org\/10.1017\/s0950268809990331","relation":{},"ISSN":["0950-2688","1469-4409"],"issn-type":[{"value":"0950-2688","type":"print"},{"value":"1469-4409","type":"electronic"}],"subject":[],"published":{"date-parts":[[2009,6,29]]}}}