title: Expansive spread of IncI1 plasmids carrying blaCMY-2 amongst Escherichia coli.
abstract: Escherichia coli is a leading cause of urinary tract infections. One of the most common antibiotic classes used to treat such infections is the β-lactams, including cephalosporins. Resistance to the third-generation cephalosporins can be caused by production of extended-spectrum β-lactamases (ESBLs) or plasmid-mediated AmpC β-lactamases. The most commonly reported AmpC β-lactamase in E. coli is CMY-2. Plasmid-mediated CMY-2 has been frequently reported in E. coli and Salmonella sp. from food-producing animals. This study aimed to elucidate the molecular characteristics of clinical E. coli isolates carrying plasmids encoding CMY-2. A total of 67 CMY-2-producing E. coli were characterised by clonal analysis and phylogenetic typing. Characterisation of the plasmids carrying blaCMY-2 included replicon typing, plasmid profiling, plasmid transferability and sequencing of the blaCMY-2 genetic environment. As a result, E. coli producing CMY-2 was found to be highly polyclonal. The majority of CMY-2-producing E. coli belonged to phylogenetic group D. IncI1 plasmids were predominant among those carrying blaCMY-2 (96%). Restriction analysis revealed a single IncI1 plasmid carrying blaCMY-2 to be predominant and present in different clones of E. coli. IS1294-ISEcp1 complex or ISEcp1 that was truncated by IS1294 was the predominant insertion sequence upstream of blaCMY-2. The homogeneous genetic environment of blaCMY-2 observed among different strains of E. coli strongly suggests horizontal transfer of this IncI1, blaCMY-2-carrying plasmid. In summary, horizontal plasmid transfer plays a major role in the spread of blaCMY-2 in E. coli.
authors: The University of Queensland, UQ Centre for Clinical Research, Building 71/918, Royal Brisbane and Women's Hospital complex, Herston 4029, QLD, Australia. Electronic address: h.sidjabat@uq.edu.au.
authors: Hanna E
authors: HE
authors: Sidjabat
authors: The University of Queensland, UQ Centre for Clinical Research, Building 71/918, Royal Brisbane and Women's Hospital complex, Herston 4029, QLD, Australia.
authors: Kwee Yong
authors: KY
authors: Seah
authors: Princess Alexandra Hospital, Brisbane, QLD, Australia.
authors: Lyndall
authors: L
authors: Coleman
authors: The University of Queensland, UQ Centre for Clinical Research, Building 71/918, Royal Brisbane and Women's Hospital complex, Herston 4029, QLD, Australia.
authors: Anna
authors: A
authors: Sartor
authors: Pathology Queensland, Herston, QLD, Australia.
authors: Petra
authors: P
authors: Derrington
authors: Pathology Queensland, Herston, QLD, Australia.
authors: Claire
authors: C
authors: Heney
authors: Princess Alexandra Hospital, Brisbane, QLD, Australia.
authors: Joan
authors: J
authors: Faoagali
authors: The University of Queensland, UQ Centre for Clinical Research, Building 71/918, Royal Brisbane and Women's Hospital complex, Herston 4029, QLD, Australia; Pathology Queensland, Herston, QLD, Australia.
authors: Graeme R
authors: GR
authors: Nimmo
authors: The University of Queensland, UQ Centre for Clinical Research, Building 71/918, Royal Brisbane and Women's Hospital complex, Herston 4029, QLD, Australia; Pathology Queensland, Herston, QLD, Australia.
authors: David L
authors: DL
authors: Paterson
mesh_terms: D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000145:classification / Q000201:enzymology* / Q000235:genetics*; D004927:Escherichia coli Infections / Q000382:microbiology*; D023061:Gene Order; D022761:Gene Transfer, Horizontal; D006801:Humans; D058889:Molecular Typing; D010802:Phylogeny; D010957:Plasmids / Q000032:analysis*; D017422:Sequence Analysis, DNA; D026801:Synteny; D014552:Urinary Tract Infections / Q000382:microbiology*; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D004251:DNA Transposable Elements; C103022:beta-lactamase CMY-2; D001618:beta-Lactamases
keywords: CMY-2; IncI1 plasmid; Plasmid analysis