遗传 ›› 2018, Vol. 40 ›› Issue (7): 585-592.doi: 10.16288/j.yczz.18-013

• 研究报告 • 上一篇    下一篇

β-内酰胺酶耐药基因blaOKP进化及其侧翼序列特征研究

邓雯文,龙梅,杨盛智,邹立扣()   

  1. 四川农业大学资源学院,成都 611130
  • 收稿日期:2018-03-21 修回日期:2018-05-03 出版日期:2018-07-20 发布日期:2018-05-28
  • 作者简介:邓雯文,硕士研究生,专业方向：微生物分子生物学。E-mail:dwenwen130@163.com
  • 基金资助:
    国家自然科学基金项目(31400066);国家自然科学基金项目(31671954);四川省科技厅应用基础研究项目资助(2017JY0118)

Evolution and the flanking sequences of β-lactamase resistance gene blaOKP

Wenwen Deng,Mei Long,Shengzhi Yang,Likou Zou()   

  1. College of Resources, Sichuan Agricultural University, Chengdu 611130, China
  • Received:2018-03-21 Revised:2018-05-03 Online:2018-07-20 Published:2018-05-28
  • Supported by:
    Supported by the National Natural Science Foundation of China(31400066);Supported by the National Natural Science Foundation of China(31671954);Supported by the National Natural Science Foundation of China(2017JY0118)

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摘要：

为研究β-内酰胺酶耐药基因blaOKP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blaOKP基因及其侧翼序列的特征,同时与不同亚型的blaSHV侧翼序列进行了对比。研究发现,blaOKP、blaSHV基因进化差异明显,分为两个进化支,其中blaOKP分为两个进化亚组(blaOKP-A和blaOKP-B)。侧翼序列分析结果表明,blaOKP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blaSHV的侧翼序列结构相似,但存在差异,主要表现为blaOKP基因的一侧与KdpC相连,blaSHV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blaSHV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blaOKP耐药基因进化缓慢的原因之一。本研究通过对blaOKP基因及其侧翼序列特征进行研究, 研究发现blaOKP基因及其侧翼序列结构保守是其相对blaSHV基因进化速度缓慢的重要原因。

关键词: 全基因组测序, blaOKP, 肺炎克雷伯氏菌, 基因环境, 基因进化

Abstract:

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.

Key words: whole genome sequencing, blaOKP, Klebsiella pneumoniae, genetic environment, gene evolution