Prevalence and molecular characterization of in clinical isolates from companion animals and humans in Henan Province, China.

BACKGROUND

The plasmid-encoded multidrug efflux pump confers bacterial resistance primarily to olaquindox, quinolones, and chloramphenicol. The aims of this study were to investigate the prevalence of among isolates from dogs, cats, and humans in Henan, China and the susceptibilities of isolates to common antibiotics.

METHODS

From 2012 to 2014, a total of 600 samples which included 400 rectal samples and 200 clinical human specimens were tested for the presence of . All isolates were screened for genes by PCR and sequencing. The MICs of 11 antimicrobial agents were determined by the broth microdilution method. A total of 30 representative -positive isolates were subjected to ERIC-PCR and MLST. Additionally, conjugation experiments and southern hybridizations were performed.

RESULTS

Of 270 isolates, 58.5% (62/106) of the isolates from dogs, 56.25% (36/64) of the isolates from cats, and 42.0% (42/100) of the isolates from humans were positive for the . Olaquindox resistance was found for 85.7%-100% of -positive isolates. Of -positive isolates from dogs, cats, and humans, ciprofloxacin resistance was inspected for 85.8%, 59.1%, and 93.8%, respectively. Several -positive isolates were demonstrated by ERIC-PCR and MLST, and have high similarity. Phylogenetic analysis showed that -positive isolates could be divided into 7 major clusters. -positive conjugants were obtained, southern hybridization verified that the gene complex was primarily located on plasmids.

CONCLUSION

In conclusion, -positive isolates were widespread in animals and humans in Henan, China. Carriage of on plasmids of isolates may facilitate the emergence of multidrug resistant and its transmission via horizontal transfer, and might pose a potential threat to public health.