文章基本信息

标题：Multilevel selection of bcrABDR-mediated bacitracin resistance in Enterococcus faecalis from chicken farms
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作者：Mu-Ya Chen ; Felipe Lira ; Hua-Qing Liang 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2016
卷号：6
期号：1
DOI：10.1038/srep34895
语种：English
出版社：Springer Nature
摘要：In this study we isolated 109 Enterococcus faecalis from chicken faecal samples in 6 provinces of China to investigate the prevalence and transmission mechanism of the bacitracin resistance locus bcrABDR in E. faecalis. Thirty-seven bcrABDR-positive E. faecalis were detected with 26 different PFGE clusters. The MLST of 14 positive strains belonged to ST16 and we also detected three new sequence types. S1-PFGE analysis indicated that the locus was located on plasmids presenting different sizes, with the most prevalent size being ~50 kb (13/37). Sequence analysis revealed that 17 out of the 37 strains harbored a 5400-bp central region, in which locus bcrABDR was bracketed by two ISEnfa1 of the same orientation. Two types of bcrABDR alleles, differing in around 10% of their sequence were found. In silico analysis showed that bcrABDR is present in a variety of bacteria including the chicken commensal Enterococcus cecorum. Our results indicate that the use of bacitracin at farms might trigger the emergence and spread of the bacitracin resistance determinant bcrABDR among human bacterial pathogens. The finding of bcrABDR in the chicken commensal E. cecorum indicates that farm animals microbiota can be an important reservoir of resistance genes with relevance for human health.