Antimicrobial resistance profiles and genotypes of extended-spectrum β-lactamase- and AmpC β-lactamase-producing Klebsiella pneumoniae isolated from dogs in Beijing, China.

OBJECTIVES: Klebsiella pneumoniae, which exists in the intestinal and respiratory tracts of humans and animals, is an important conditional pathogen in many animals. The aim of the current study was to investigate the antimicrobial resistance profiles and genotypes of extended-spectrum β-lactamase (ESBL)- and AmpC β-lactamase-producing K. pneumoniae isolated from dogs.

METHODS: A total of 285 isolates, collected from faecal and urine samples of diseased dogs in a Veterinary Teaching Hospital in Beijing, were characterised by antimicrobial susceptibility testing and screened for ESBL and AmpC β-lactamase phenotypes. The relevant genes were identified by polymerase chain reaction and sequencing.

RESULTS: All K. pneumoniae isolates were susceptible to meropenem, while the rates of resistance to the remaining 27 tested antimicrobials ranged from 24% to 97%. A total of 53% and 18% of K. pneumoniae isolates were positive for ESBL and AmpC β-lactamase production, respectively. ESBL/AmpC-producing strains were significantly resistant to more antimicrobial agents compared non-ESBL/AmpC-producing strains (P<0.05). CTX-M groups 1 and 9, and DHA-1 were the predominant genotypes of the ESBL/AmpC-producing K. pneumoniae isolates.

CONCLUSIONS: In conclusion, the high percentage of drug resistance among K. pneumoniae isolates suggests that routine detection of ESBL production by reliable laboratory methods is required in small animal clinical practice.