{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T22:59:20Z","timestamp":1774306760381,"version":"3.50.1"},"reference-count":33,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2020,2,7]],"date-time":"2020-02-07T00:00:00Z","timestamp":1581033600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>In our previous study, extended spectrum \u03b2-lactamase (ESBL)-producing Escherichia coli (ESBLEC) were isolated from healthy Thoroughbred racehorse feces samples in Japan. Some ESBL genes were predicted to be located on the conjugative plasmid. PCR-based replicon typing (PBRT) is a useful method to monitor and detect the association of replicons with specific plasmid-borne resistant genes. This study aimed to evaluate the plasmid replicon associated with ESBLEC isolated from healthy Thoroughbred racehorses at Japan Racing Association Training Centers in Japan. A total of 24 ESBLECs isolated from 23 (10.8%) individual Thoroughbred racehorse feces samples were used in this study. ESBL gene transfer was performed using a conjugation assay. Then, replicon types of ESBLEC isolates and their transconjugants were determined using PBRT. Pulsed-field gel electrophoresis (PFGE) was performed to look at the clonality of the ESBLECs isolates. ESBLECs were detected from 10.8% of healthy Thoroughbred racehorses. The blaCTX-M-2 was identified as the dominant type of ESBL gene, followed by blaCTX-M-1 and blaTEM-116. In this study, only the blaCTX-M-2 and the IncI1 plasmid were transferred to transconjugants. The PFGE results showed that ESBL genes were distributed in diversity of ESBLECs. This finding suggested that the IncI1 plasmid was associated with the dissemination of blaCTX-M-2 in Thoroughbred racehorses in Japan.<\/jats:p>","DOI":"10.3390\/antibiotics9020070","type":"journal-article","created":{"date-parts":[[2020,2,7]],"date-time":"2020-02-07T11:50:28Z","timestamp":1581076228000},"page":"70","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["IncI1 Plasmid Associated with blaCTX-M-2 Transmission in ESBL-Producing Escherichia coli Isolated from Healthy Thoroughbred Racehorse, Japan"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8749-0270","authenticated-orcid":false,"given":"Eddy","family":"Sukmawinata","sequence":"first","affiliation":[{"name":"Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-1692, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ryoko","family":"Uemura","sequence":"additional","affiliation":[{"name":"Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan"},{"name":"Center for Animal Disease Control, University of Miyazaki, Miyazaki 889-2192, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wataru","family":"Sato","sequence":"additional","affiliation":[{"name":"Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shuya","family":"Mitoma","sequence":"additional","affiliation":[{"name":"Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-1692, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takuya","family":"Kanda","sequence":"additional","affiliation":[{"name":"Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-1692, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masuo","family":"Sueyoshi","sequence":"additional","affiliation":[{"name":"Graduate School of Medicine and Veterinary Medicine, University of Miyazaki, Miyazaki 889-1692, Japan"},{"name":"Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan"},{"name":"Center for Animal Disease Control, University of Miyazaki, Miyazaki 889-2192, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,2,7]]},"reference":[{"key":"ref_1","first-page":"e000203","article-title":"Extended-spectrum \u03b2-lactamase-encoding genes are spreading on a wide range of Escherichia coli plasmids existing prior to the use of third-generation cephalosporins","volume":"4","author":"Branger","year":"2018","journal-title":"Microb. 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