Prevalence of the fosfomycin-resistance determinant, fosB3, in Enterococcus faecium clinical isolates from China
Prevalence of the fosfomycin-resistance determinant, fosB3, in Enterococcus faecium clinical isolates from China
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中国粪肠球菌临床分离株中磷霉素耐药决定簇 fosB3 的流行情况。
DOI：
10.1099/jmm.0.077701-0
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发表时间：
2014-11-01
影响因子：
3
通讯作者：
Wang, Minggui
中科院分区：
文献类型：
--
作者：
Chen, Chunhui;Xu, Xiaogang;Wang, Minggui
为了调查屎肠球菌磷霉素耐药（fos）决定簇的流行情况，于2008年1月至2009年12月期间从中国各地医院收集临床菌株。药敏试验后，采用PCR和测序方法对所有分离株的fos基因和万古霉素耐药株的货车基因进行鉴定。用fosB阳性的E.对fosB 3基因两侧的DNA片段进行了测序，并分析了fosB 3的遗传环境。耐磷霉素E.通过多位点序列分型（MLST）和PFGE进一步表征了屎肠球菌（FREF）菌株。在145株E. 10株对磷霉素耐药，MIC>1024 mg l（-1），其中6株耐万古霉素，其中5株vanA阳性，6株vanM阳性。所有10株FREF菌株均携带fosB 3基因。磷霉素抗性和fosB 3可以通过接合转移从9个菌株。fosB 3和tnpA基因位于所有FREF菌株的环状DNA中间体中，并在4个vanA阳性FREF分离株中插入到vanA转座子Tn 1546中。10个不同的PFGE类型和7个MLST类型中发现的10个fosB 3阳性菌株，而所有菌株属于共同的克隆复合体CC 17。因此，可转移的磷霉素耐药决定簇fosB 3在大肠杆菌中起重要作用。屎肠菌对磷霉素的抗药性。
In order to investigate the prevalence of fosfomycin-resistance (fos) determinants in Enterococcus faecium, clinical strains were collected from hospitals throughout China between January 2008 and December 2009. Antimicrobial susceptibility testing was performed, after which the fos genes in all isolates and van genes in vancomycin-resistant isolates were characterized by PCR and sequencing. Conjugation experiments were carried out with fosB-positive E. faecium, DNA fragments flanking the fosB3 gene were sequenced and the genetic environment of fosB3 was analysed. Fosfomycin-resistant E. faecium (FREF) strains were characterized further by multilocus sequence typing (MLST) and PFGE. Among 145 E. faecium clinical isolates, 10 were resistant to fosfomycin with MICs>1024 mg l(-1) including six vancomycin-resistant strains of which five were vanA-positive and the sixth vanM-positive. All ten FREF strains harboured the fosB3 gene. Fosfomycin resistance and fosB3 could be transferred by conjugation from nine isolates. The fosB3 and tnpA genes were located in a circular DNA intermediate in all FREF strains and reversely inserted into vanA transposon Tn1546 in four vanA-positive FREF isolates. Ten different PFGE types and seven MLST types were found among the ten fosB3-positive isolates, while all strains belonged to the common clonal complex CC17. In conclusion, the transferable fosfomycin-resistance determinant fosB3 plays an important role in E. faecium resistance to fosfomycin in China.