Detection of the staphylococcal multiresistance gene cfr in Escherichia coli of domestic-animal origin
Detection of the staphylococcal multiresistance gene cfr in Escherichia coli of domestic-animal origin
复制标题
家畜源性大肠杆菌中葡萄球菌多重耐药基因cfr的检测
DOI：
10.1093/jac/dks020
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发表时间：
2012-05-01
影响因子：
5.2
通讯作者：
Shen, Jianzhong
中科院分区：
文献类型：
--
作者：
Wang, Yang;He, Tao;Shen, Jianzhong
目的调查家畜大肠杆菌中多重耐药基因cfr的存在情况及其遗传环境。用PCR方法对猪、鸡、鸭大肠杆菌分离株进行cfr基因的筛选。通过Southern杂交确定cfr基因的位置，通过接合和转化检测cfr基因的可转移性，并通过改进的随机引物步移策略测定cfr基因侧翼区的序列。通过快速扩增5个cDNA末端（5 RACE）定位cfr转录起始位点，分析了cfr启动子序列的位置。Southern杂交表明cfr基因位于约110 kb的质粒pEC-01上。一个1545 bp的携带cfr的片段，其序列与携带cfr的质粒pSCFS 1的序列相同，两侧是两个相同方向的IS 26元件。IS 26转座后产生了一个新的杂合启动子，其中35区是IS 26的左反向重复序列的一部分，而10样序列是原始cfr上游区的一部分，据我们所知，这是cfr基因在天然大肠杆菌中的首次报道。大肠杆菌菌株。有必要继续监测家畜来源的革兰氏阴性菌中cfr基因的存在。
To investigate the presence and the genetic environment of the multiresistance gene cfr in Escherichia coli found in domestic animals.A total of 1230 E. coli isolates, collected from pigs, chickens and ducks, were screened by PCR for the cfr gene. The location of the cfr gene was determined by Southern blotting, the transferability of cfr gene was tested by conjugation and transformation, and the regions flanking the cfr gene were sequenced by a modified random primer walking strategy. The location of the cfr promoter sequence was analysed by mapping the cfr transcription start site using rapid amplification of 5 cDNA ends (5 RACE).Only a single strain from the nasal swab of a pig harboured the cfr gene. Southern blotting indicated that the cfr gene was located on a approximate to 110 kb plasmid, designated pEC-01. A cfr-carrying segment of 1545 bp with a sequence identical to that of the cfr-harbouring plasmid pSCFS1 was flanked by two IS26 elements in the same orientation. The IS26 transposition created a new hybrid promoter in which the 35 region was part of the left inverted repeat of IS26 while the 10-like sequence was part of the original cfr upstream region.To the best of our knowledge, this is the first report of the cfr gene in a naturally occurring E. coli strain. Continued surveillance of the presence of the cfr gene in Gram-negative bacteria of domestic-animal origin is warranted.