Journal Article

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Antimicrobial Agents and Chemotherapy

Antimicrob.Agents Chemother.

58

2

789

794

LR: 20150422; JID: 0315061; 0 (Bacterial Proteins); 0 (beta-Lactams); EC 3.5.2.- (beta-lactamase CTX-M-15); EC 3.5.2.- (beta-lactamase SHV-12); EC 3.5.2.6 (beta-Lactamases); OID: NLM: PMC3910873; 2013/11/18 [aheadofprint]; ppublish

United States

1098-6596; 0066-4804

PMID: 24247146

eng

Journal Article; IM

10.1128/AAC.00752-13 [doi]

Unknown(0)

24247146

Recent reports raised concerns about the role that farm stock may play in the dissemination of extended-spectrum beta-lactamase (ESBL)-producing bacteria. This study characterized the ESBLs in two Escherichia coli and three Klebsiella pneumoniae subsp. pneumoniae isolates from cases of clinical bovine mastitis in the United Kingdom. Bacterial culture and sensitivity testing of bovine mastitic milk samples identified Gram-negative cefpodoxime-resistant isolates, which were assessed for their ESBL phenotypes. Conjugation experiments and PCR-based replicon typing (PBRT) were used for characterization of transferable plasmids. E. coli isolates belonged to sequence type 88 (ST88; determined by multilocus sequence typing) and carried blaCTX-M-15 and blaTEM-1, while K. pneumoniae subsp. pneumoniae isolates carried blaSHV-12 and blaTEM-1. Conjugation experiments demonstrated that blaCTX-M-15 and blaTEM-1 were carried on a conjugative plasmid in E. coli, and PBRT identified this to be an IncI1 plasmid. The resistance genes were nontransferable in K. pneumoniae subsp. pneumoniae isolates. Moreover, in the E. coli isolates, an association of ISEcp1 and IS26 with blaCTX-M-15 was found where the IS26 element was inserted upstream of both ISEcp1 and the blaCTX-M promoter, a genetic arrangement highly similar to that described in some United Kingdom human isolates. We report the first cases in Europe of bovine mastitis due to E. coli CTX-M-15 and also of bovine mastitis due to K. pneumoniae subsp. pneumoniae SHV-12 beta-lactamases in the United Kingdom. We also describe the genetic environment of blaCTX-M-15 and highlight the role that IncI1 plasmids may play in the spread and dissemination of ESBL genes, which have been described in both human and cattle isolates.

Timofte,D., Maciuca,I.E., Evans,N.J., Williams,H., Wattret,A., Fick,J.C., Williams,N.J.

School of Veterinary Science, University of Liverpool, Leahurst, Cheshire, United Kingdom.

20131118

PMC3910873

http://vp9py7xf3h.search.serialssolutions.com/?charset=utf-8&pmid=24247146

2014