title: IncA/C plasmid-mediated spread of CMY-2 in multidrug-resistant Escherichia coli from food animals in China.
abstract: OBJECTIVE
  To obtain a broad molecular epidemiological characterization of plasmid-mediated AmpC β-lactamase CMY-2 in Escherichia coli isolates from food animals in China.
  
  
  METHODS
  A total of 1083 E. coli isolates from feces, viscera, blood, drinking water, and sub-surface soil were examined for the presence of CMY-2 β-lactamases. CMY-2-producing isolates were characterized as follows: the blaCMY-2 genotype was determined using PCR and sequencing, characterization of the blaCMY-2 genetic environment, plasmid sizing using S1 nuclease pulsed-field gel electrophoresis (PFGE), PCR-based replicon typing, phylogenetic grouping, XbaI-PFGE, and multi-locus sequence typing (MLST).
  
  
  RESULTS
  All 31 CMY-2 producers were only detected in feces, and presented with multidrug resistant phenotypes. All CMY-2 strains also co-harbored genes conferring resistance to other antimicrobials, including extended spectrum β-lactamases genes (blaCTX-M-14 or blaCTX-M-55), plasmid-mediated quinolone resistance determinants (qnr, oqxA, and aac-(6')-Ib-cr), floR and rmtB. The co-transferring of blaCMY-2 with qnrS1 and floR (alone and together) was mainly driven by the Inc A/C type plasmid, with sizes of 160 or 200 kb. Gene cassette arrays inserted in the class 1 or class 2 integron were amplified among 12 CMY-2 producers. CMY-2 producers belonged to avirulent groups B1 (n = 12) and A (n = 11), and virulent group D (n = 8). There was a good correlation between phylogenetic groups and sequence types (ST). Twenty-four STs were identified, of which the ST complexes (STC) 101/B1 (n = 6), STC10/A (n = 5), and STC155/B1 (n = 3) were dominant.
  
  
  CONCLUSIONS
  CMY-2 is the dominant AmpC β-lactamase in food animals and is associated with a transferable replicon IncA/C plasmid in the STC101, STC10, and STC155 strains.
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou, China.
authors.forename: Yu-Fang
authors.initials: YF
authors.lastname: Guo
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou, China.
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou, China.
authors.forename: Si-Qi
authors.initials: SQ
authors.lastname: Ren
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.affiliation: Laboratory of Clinical Microbiology, Institute of Veterinary Medicine, Guangdong Academy of Agriculture Sciences, Guangzhou, China.
authors.forename: Dian-Hong
authors.initials: DH
authors.lastname: Lü
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou, China.
authors.forename: Zhen-Ling
authors.initials: ZL
authors.lastname: Zeng
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou, China.
authors.forename: Ya-Hong
authors.initials: YH
authors.lastname: Liu
authors.affiliation: College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University (SCAU), Guangzhou, China.
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Jiang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D002681:China; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D005516:Food Microbiology; D032023:Integrons / Q000235:genetics; D017720:Molecular Epidemiology; D010957:Plasmids / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C103022:beta-lactamase CMY-2; C048795:AmpC beta-lactamases; D001618:beta-Lactamases