IncA/C plasmid-mediated spread of CMY-2 in multidrug-resistant Escherichia coli from food animals in China

• Published in: PloS one Vol. 9; no. 5; p. e96738
• Main Authors: Guo, Yu-Fang, Zhang, Wen-Hui, Ren, Si-Qi, Yang, Lin, Lü, Dian-Hong, Zeng, Zhen-Ling, Liu, Ya-Hong, Jiang, Hong-Xia
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 09.05.2014; Public Library of Science (PLoS)
• Subjects: Animals; Anti-Bacterial Agents - pharmacology; Antibiotics; Antimicrobial agents; Bacterial Proteins - genetics; beta-Lactamases - genetics; Biology and Life Sciences; China; Drinking water; Drug resistance; Drug Resistance, Multiple, Bacterial - genetics; E coli; Epidemiology; Escherichia coli; Escherichia coli - drug effects; Escherichia coli - enzymology; Escherichia coli - genetics; Escherichia coli - isolation & purification; Feces; Food; Food Microbiology; Gel electrophoresis; Gene sequencing; Genes; Integrons - genetics; Klebsiella pneumoniae; Laboratories; Medicine and Health Sciences; Microbial drug resistance; Molecular Epidemiology; Multidrug resistance; Multidrug resistant organisms; Nuclease; Pharmaceutical sciences; Phylogenetics; Phylogeny; Plasmids; Plasmids - genetics; Pulsed-field gel electrophoresis; Salmonella; Salmonella Typhimurium; Soil surfaces; Soil water; Strains (organisms); Studies; Surveillance; Veterinary colleges; Veterinary medicine; Viscera; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0096738

To obtain a broad molecular epidemiological characterization of plasmid-mediated AmpC β-lactamase CMY-2 in Escherichia coli isolates from food animals in China. 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). 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. 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.