Ma Yongping, Xie Ting-Ting, Hu Qiongwen, Qiu Zongyin, Song Fangzhou
Key Laboratory of Biochemistry and Molecular Biology, Molecular Medical and Cancer Research Center, Chongqing Medical University, Yuzhong District, Yi XueYuan Road, No. 1, Chongqing 400016, People's Republic of China.
Can J Microbiol. 2015 Feb;61(2):124-30. doi: 10.1139/cjm-2014-0581. Epub 2014 Nov 4.
A resident plasmid, pBIF10, was isolated from Bifidobacterium longum B200304, and the full-length sequence of pBIF10 was analyzed. In this sequence, we identified at least 17 major open reading frames longer than 200 bp. A tetracycline resistance gene, tetQ, was identified and verified to confer antibiotic resistance to tetracycline. The plasmid replicon with replication protein B gene (repB) and a typical iteron was identified in pBIF10. An artificial clone vector was constructed with the replicon of pBIF10; the results showed that repB controlled plasmid replication in other bifidobacteria host cells at low transformation frequency. Taken together, the analysis and characterization of pBIF10 provided necessary information for the understanding of antibiotic resistance mediated by a plasmid in a Bifidobacterium strain. GC% and repB sequence analyses indicated that pBIF10 was a molecular hybrid of at least 2 other bacterial genera plasmids.
从长双歧杆菌B200304中分离出一个常驻质粒pBIF10，并对pBIF10的全长序列进行了分析。在该序列中，我们鉴定出至少17个长度超过200 bp的主要开放阅读框。鉴定出一个四环素抗性基因tetQ，并证实其赋予对四环素的抗生素抗性。在pBIF10中鉴定出具有复制蛋白B基因（repB）和典型重复序列的质粒复制子。构建了一个含有pBIF10复制子的人工克隆载体；结果表明，repB在低转化频率下控制着其他双歧杆菌宿主细胞中的质粒复制。综上所述，pBIF10的分析和表征为理解双歧杆菌菌株中质粒介导的抗生素抗性提供了必要信息。GC%和repB序列分析表明，pBIF10是至少2个其他细菌属质粒的分子杂交体。
