biostudies-literatureFindlay JMRFUKRI | MRC | Medical Research FoundationUKRI | Biotechnology and Biological Sciences Research CouncilMedical Research FoundationUKRI | Natural Environment Research CouncilNatural Environment Research CouncilBiotechnology and Biological Sciences Research Councile01842-20https://www.ebi.ac.uk/biostudies/studies/S-EPMC7755243biostudies-literatureUnknown87(1)Third-generation cephalosporin resistance (3GC-R) in <i>Escherichia coli</i> is a rising problem in human and farmed-animal populations. We conducted whole-genome sequencing analysis of 138 representative 3GC-R isolates previously collected from dairy farms in southwest England and confirmed by PCR to carry acquired 3GC-R genes. This analysis identified <i>bla</i> _CTX-M (131 isolates encoding CTX-M-1, -14, -15, -and 32 and the novel variant CTX-M-214), <i>bla</i> _CMY-2 (6 isolates), and <i>bla</i> _DHA-1 (1 isolate). A highly conserved plasmid was identified in 73 isolates, representing 27 <i>E. coli</i> sequence types. This novel ∼220-kb IncHI2 plasmid carrying <i>bla</i> _CTX-M-32 was sequenced to closure and designated pMOO-32. It was found expeApplied and environmental microbiologyMolecular Epidemiology of Escherichia coli Producing CTX-M and pAmpC β-Lactamases from Dairy Farms Identifies a Dominant Plasmid Encoding CTX-M-32 but No Evidence for Transmission to Humans in the Same Geographical Region.PMC7755243MRF_MRF-145-0004-TPG-AVISONE/N01961X/1BB/T004592/1MRF-145-0004-TPG-AVISOMounsey OAvison MBMorley KSchubert HFindlay JGould VCLee WWYCogan TANewbold NReyher KKfalseMolecular Epidemiology of Escherichia coli Producing CTX-M and pAmpC β-Lactamases from Dairy Farms Identifies a Dominant Plasmid Encoding CTX-M-32 but No Evidence for Transmission to Humans in the Same Geographical Region.Third-generation cephalosporin resistance (3GC-R) in <i>Escherichia coli</i> is a rising problem in human and farmed-animal populations. We conducted whole-genome sequencing analysis of 138 representative 3GC-R isolates previously collected from dairy farms in southwest England and confirmed by PCR to carry acquired 3GC-R genes. This analysis identified <i>bla</i> _CTX-M (131 isolates encoding CTX-M-1, -14, -15, -and 32 and the novel variant CTX-M-214), <i>bla</i> _CMY-2 (6 isolates), and <i>bla</i> _DHA-1 (1 isolate). A highly conserved plasmid was identified in 73 isolates, representing 27 <i>E. coli</i> sequence types. This novel ∼220-kb IncHI2 plasmid carrying <i>bla</i> _CTX-M-32 was sequenced to closure and designated pMOO-32. It was found expe2020-01-01T00:00:00Z2020 Dec2025-04-20T00:15:19.509Z2022-02-10T15:03:57.044ZS-EPMC77552433306719710.1128/aem.01842-2010.1128/AEM.01842-20