天津医药

• 论著 •    

鲍曼不动杆菌临床株Ⅰ 类整合子和 ISCR1 的分布及结构研究

李娟1,郝邯生2,王悦3   

  1. 1. 天津医科大学研究生院
    2. 中国人民武装警察部队后勤学院附属医院感染科
    3. 天津医科大学第二医院感染科
  • 收稿日期:2012-10-24 修回日期:2013-01-10 出版日期:2013-07-15 发布日期:2013-07-15
  • 通讯作者: 郝邯生

A study on the the distribution and structure of class I integron and ISCR1 in clinical isolates of Acinetobacter baumannii

LI Juan 1,HAO Hansheng 2,WANG Yue 3   

  1. 1. Graduate School of Tianjin Medical University, Tianjin 300070, China
    2. Department of Infectious Disease, The Affiliated Hospital of College of The Armed Police
    3. Department of Infectious Disease， The Second Hospital of Tianjin Medical University
  • Received:2012-10-24 Revised:2013-01-10 Published:2013-07-15 Online:2013-07-15
  • Contact: HAO Hansheng

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摘要： 　　　

【摘要】 目的 了解鲍曼不动杆菌临床株中Ⅰ 类整合子、插入序列共同区（ISCR1）的分布情况， 研究它们所携带的耐药基因。 方法 收集来自临床的 51 株多重耐药鲍曼不动杆菌， PCR 检测Ⅰ 类整合酶基因、Ⅰ 类整合子可变区、ISCR1 和 ISCR1 下游基因环境， DNA 序列分析检测Ⅰ 类整合子和 ISCR1 携带的耐药基因， PCR-mapping检测Ⅰ 类整合子与 ISCR1 的关系。 结果  51 株多重耐药鲍曼不动杆菌中Ⅰ 类整合酶基因阳性 45 株， 32 株检出可变区结构，DNA 序列分析显示携带 aacA4-catB8-aadA1、aacC1-orfA-orfB-aadA1、blaPSE-1-aadA2-cmlA1-aadA1 3 种形式的耐药基因盒； ISCR1 阳性 22 株， 5 株检出 ISCR1 下游基因， DNA 序列分析结果为 qnrA1-ampR。 PCR-mapping显示 20 株鲍曼不动杆菌中的 ISCR1 直接连接在Ⅰ 类整合子 3′ 保守区下游。 结论 Ⅰ 类整合子、ISCR1 在鲍曼不动杆菌耐药中起重要作用， 且Ⅰ 类整合子和 ISCR1 可以串联形式存在于鲍曼不动杆菌中。

关键词: 鲍氏不动杆菌, 整合子类, 多态性, 限制性片段长度, 聚合酶链反应, 插入序列共同区

Abstract: [Abstract]    Objective    To investigate the distribution and the antibiotic resistance genes carried by class Ⅰ integron and insertion sequence common region（ISCR1） among clinical isolates of Acinetobacter baumannii. Methods   Fifty-one clinical isolates of multidrug-resistant Acinetobacter baumannii were collected. Polymerase chain reaction method was used to detect the class Ⅰ integrase gene, variable region of classⅠ integron, ISCR1 and genes related to antibiotics resistance located downstream of ISCR1 in 51 multidrug-resistant Acinetobacter baumannii. Antibiotics resistance genes carried by classⅠ integron and ISCR1 were performed by DNA sequencing. The relationship between classⅠ integron and ISCR1 was detected by PCR-mapping. Results Among 51 multidrug-resistant Acinetobacter baumannii isolates, 45 strains were found containing classⅠ integrase genes, 32 strains were found containing variable regions. Sequencing results showed that the gene cassette arrays were aacA4-catB8-aadA1, aacC1-orfA-orf-B-aadA1 and blaPSE-1-aadA2-cmlA1-aadA1. Twenty-two strains were found containing ISCR1 and 5 strains were found containing resistance genes located downstream of ISCR1.
DNA sequencing results showed the resistant gene of qnrA1-ampR. The results of PCR-mapping showed that ISCR1 located directly downstream of 3' conserved segment of classⅠ integron in 20 Acinetobacter baumannii strains. Conclusion ClassⅠ integron and ISCR1 play an important role in mechanisms of drug resistance of Acinetobacter baumannii. ClassⅠ integron and ISCR1 could connect in series in Acinetobacter baumannii.

Key words: Acinetobacterbaumannii, integrons, polymorphism, restriction fragment length, Polymerase chain reaction, insertion sequence common region