{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,9]],"date-time":"2026-06-09T14:09:56Z","timestamp":1781014196447,"version":"3.54.1"},"reference-count":29,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2020,3,6]],"date-time":"2020-03-06T00:00:00Z","timestamp":1583452800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["2018R1D1A1B07049433"],"award-info":[{"award-number":["2018R1D1A1B07049433"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>We investigated fosfomycin susceptibility in Escherichia coli clinical isolates from South Korea, including community-onset, hospital-onset, and long-term care facility (LTCF)-onset isolates. The resistance mechanisms and genotypes of fosfomycin-resistant isolates were also identified. Finally, the in vitro efficacy of combinations of fosfomycin with other antibiotics were examined in susceptible or extended spectrum \u03b2-lactamase (ESBL)-producing E. coli isolates. The fosfomycin resistance rate was 6.7% and was significantly higher in LTCF-onset isolates than community-onset and hospital-onset isolates. Twenty-one sequence types (STs) were identified among 19 fosfomycin-resistant E. coli isolates, showing diverse genotypes. fosA3 was found in only two isolates, and diverse genetic variations were identified in three genes associated with fosfomycin resistance, namely, GlpT, UhpT, and MurA. Some fosfomycin-resistant E. coli isolates carried no mutations. In vitro time-kill assays showed that fosfomycin alone did not exhibit an excellent killing activity, compared with ciprofloxacin in susceptible isolates and with ertapenem in ESBL producers. However, combining fosfomycin with cefixime or piperacillin-tazobactam eradicated susceptible or ESBL-producing isolates, respectively, even with 0.5\u00d7 minimum inhibitory concentrations. Overall, we found a relatively high fosfomycin resistance rate in E. coli isolates from South Korea. Based on their genotypes and resistance mechanisms, most of the fosfomycin-resistant E. coli isolates might occur independently. Antibiotic combinations with fosfomycin could be a suitable therapeutic option for infections caused by E. coli isolates.<\/jats:p>","DOI":"10.3390\/antibiotics9030112","type":"journal-article","created":{"date-parts":[[2020,3,6]],"date-time":"2020-03-06T09:26:41Z","timestamp":1583486801000},"page":"112","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":26,"title":["Fosfomycin Resistance in Escherichia coli Isolates from South Korea and in vitro Activity of Fosfomycin Alone and in Combination with Other Antibiotics"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2032-9538","authenticated-orcid":false,"given":"Hyeri","family":"Seok","sequence":"first","affiliation":[{"name":"Division of Infectious Diseases, Department of Medicine, Korea University Ansan Hospital, Korea University College of Medicine, Ansan 15355, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ji Young","family":"Choi","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon 16419, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu Mi","family":"Wi","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon 51353, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dae Won","family":"Park","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Department of Medicine, Korea University Ansan Hospital, Korea University College of Medicine, Ansan 15355, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7464-9780","authenticated-orcid":false,"given":"Kyong Ran","family":"Peck","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0978-1937","authenticated-orcid":false,"given":"Kwan Soo","family":"Ko","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon 16419, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,3,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"872","DOI":"10.1016\/j.clinthera.2013.03.022","article-title":"Antimicrobial susceptibility of inpatient urinary tract isolates of gram-negative bacilli in the United States: Results from the study for monitoring antimicrobial resistance trends (SMART) program: 2009\u20132011","volume":"35","author":"Bouchillon","year":"2013","journal-title":"Clin. 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