摘要
为研究β-内酰胺酶耐药基因bla_(OKP)进化及其侧翼序列情况,本文通过全基因组测序技术对肺炎克雷伯氏菌进行测定,分析了其中bla_(OKP)基因及其侧翼序列的特征,同时与不同亚型的bla_(SHV)侧翼序列进行了对比。研究发现,bla_(OKP)、bla_(SHV)基因进化差异明显,分为两个进化支,其中bla_(OKP)分为两个进化亚组(bla_(OKP-A)和bla_(OKP-B))。侧翼序列分析结果表明,bla_(OKP)基因的侧翼序列中无可移动遗传元件,与染色体介导的基因bla_(SHV)的侧翼序列结构相似,但存在差异,主要表现为bla_(OKP)基因的一侧与Kdp C相连,bla_(SHV)基因的一侧与RecF相连并具有ygbN-ygbM-ygbK结构。同时由质粒介导的bla_(SHV)基因的两侧存在多种可移动遗传元件。这些结构差异可能是导致bla_(OKP)耐药基因进化缓慢的原因之一。本研究通过对bla_(OKP)基因及其侧翼序列特征进行研究,研究发现bla_(OKP)基因及其侧翼序列结构保守是其相对bla_(SHV)基因进化速度缓慢的重要原因。
blaOKP genes are chromosomally encoded beta-lactamases that mediate several classes of antibiotics resistance.To investigate the evolution and flanking sequences of OKP beta-lactamase gene,the gene blaOKP and its flanking sequences from a newly isolated Klebsiella pneumoniae were studied using whole genome sequencing.The flanking sequences of different variant blaOKP genes and blaSHV,another plasmid-encoded beta-lactamase gene,were then compared.These studies show that the blaOKP and blaSHV genes evolve differently and belong to two different evolution branches.The blaOKP gene variants can be divided into subgroups:blaOKP-A and blaOKP-B.Although both blaOKP and blaSHV genes have no mobile genetic elements in their flanking sequences,their genetic environments are quite different.The blaOKP gene is adjacent to KdpC while blaSHV gene is flanked by RecF and ygbN-ygbM-ygbK.Furthermore,there are a variety of mobile genetic elements in the neighboring sequence plasmid-encoded blaSHV genes that are absent in blaOKP genes.These structural differences may slow the evolution of blaOKP gene.Collectively,we demonstrate that the evolution and flanking sequence of blaOKP gene are different from those of the blaSHV gene,which could be an important reason for its relatively slow evolution.
作者
邓雯文
龙梅
杨盛智
邹立扣
Wenwen Deng;Mei Long;Shengzhi Yang;Likou Zou(College of Resources,Sichuan Agricultural University,Chengdu 611130,China)
出处
《遗传》
CAS
CSCD
北大核心
2018年第7期591-598,共8页
Hereditas（Beijing)
基金
国家自然科学基金项目(编号:31400066
31671954)
四川省科技厅应用基础研究项目(编号:2017JY0118)资助~~
