Genomic Characterization of Multiple Antibiotic-Resistant Enterococcus in Farm Animals in Ningxia Province, China

TL;DR

This study analyzed antibiotic-resistant Enterococcus bacteria in farm animals in China and found high resistance rates and potential transmission risks to humans.

Contribution

The study provides a comprehensive genomic and phenotypic characterization of multi-antibiotic-resistant Enterococcus isolates from farm animals in Ningxia, China.

Findings

96.6% of Enterococcus isolates were multi-antibiotic resistant.

Enterococcus from pigs showed significantly higher resistance than isolates from other animals.

ST16 was identified as an important pathogenic Enterococcus type.

Abstract

Background/Objectives: In an era of increasing bacterial resistance, Enterococcus, as a reservoir of antibiotic resistance genes, poses a serious threat to public health. Methods: This study conducted antibiotic susceptibility tests, whole-genome sequencing, and bioinformatics analysis on 89 Enterococcus isolates from chickens, pigs, cattle, and sheep in Ningxia Autonomous Region. Results: The resistance rates of Enterococcus to clindamycin, cefoxitin, sulfamethoxazole, and tamoxifen were all above 95%, and 96.6% (86/89) of the isolates were multi-antibiotic resistant. There were significant differences in resistance phenotypes among different species, with Enterococcus from pigs showing significantly higher resistance than those from other animals. optrA was commonly found in Enterococcus from pigs, accounting for 61.5% (8/13). ST480, ST16, ST116, and ST300 were the main MLST types, and ST16 was one of the important pathogenic Enterococcus types. Conclusions: The study revealed the occurrence of inter-species transmission events of Enterococcus. In conclusion, this study comprehensively described the resistance spectrum, sequence characteristics, and transmission features of resistance genes in Enterococcus isolated from farm animals, and emphasized the possibility of the spread of resistance genes carried by Enterococcus from farm animals to humans.

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