bla-producing multidrug-resistant Escherichia coli isolated from a companion dog in China.

OBJECTIVES

This study characterised a bla-producing Escherichia coli isolate from a companion dog.

METHODS

The E. coli strain was isolated from a surveillance study of carbapenem-resistant Gram-negative bacteria from companion animals in the Animal Teaching Hospital of China Agricultural University (Beijing, China) in 2013. Species identification was performed using an API 20E system and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Minimum inhibitory concentrations (MICs) of various antimicrobial agents were determined by agar dilution. Multilocus sequence typing (MLST) was performed and various carbapenemase genes, including bla, bla, bla, bla, bla, bla, bla, bla, bla, bla, bla, bla, bla, bla, bla, bla and bla were screened by PCR. S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern blotting as well as a modified random primer walking strategy were performed to analyse the location and genetic environment of bla.

RESULTS

An E. coli isolate belonging to ST167 was found to be positive for the bla gene and exhibited resistance to β-lactams, tetracycline, gentamicin, fosfomycin and ciprofloxacin. The bla gene in this strain was located on an ca. 150-kb plasmid and the flanking sequences of the bla-carrying region (a common gene cluster, ΔISAba125-bla-ble-trpF-ΔdsbC) exhibited >99% identity to the corresponding regions of bla-harboring plasmids in nosocomial E. coli ST131 isolates.

CONCLUSIONS

This is the first report of bla-producing ST167 E. coli in a companion dog. Companion animals harbouring carbapenemase-producing isolates are an upcoming public health threat and it is worthy paying attention to the emergence of carbapenem resistance in companion animals.