【作者】 瞿婷婷； 俞云松； 周建英； 王杰； 陈亚岗； 郑慧娟； 李兰娟；

【Author】 YU Yun-song, QU Ting-ting, ZHOU Jian-ying, WANG Jie, CHEN Ya-gang, ZHENG Hui-juan Infectious Disease Dept, The 1st Affiliated Hospital, Medical School, Zhejiang University, The key lab. of Infectious Diseases of Public Health Ministry, Hangzhou; Respiratory Dept, The 1st Affiliated Hospital, Medical School, Zhejiang University, Hangzhou

【机构】 浙江大学附属第一医院传染病研究所； 浙江大学附属第一医院呼吸科；

【摘要】 目的明确我国五个不同地区医院中亚胺培南耐药铜绿假单胞菌中金属酶的基因型分布及其基因定位,推测耐药基因的来源及传播机制。方法收集国内五个地区临床分离的140株亚胺培南耐药的铜绿假单胞菌。采用琼脂稀释法及Etest法检测其对常用十种抗菌药物的耐药性;双纸片法进行金属酶筛选,PCR法扩增金属酶基因型和整合子;采用脉冲凝胶电泳(PFGE)对产金属酶菌株进行同源性分析;采用接合试验、质粒的提取及电转化、DNAsouthern杂交确定基因定位。结果金属酶筛选试验共检测出产金属酶表型阳性菌株12株。PCR扩增出13株VIM-2阳性菌株,其中12株扩增出两种不同长度的整合子,分别携带aacA4、VIM-2 及aacA4、VIM-2、aadB基因盒。Southem杂交证实VIM-2基因位于XbaI酶切染色体PFGE大约50kb大小的片段上。讨论我国亚胺培南耐药铜绿假单胞菌中金属酶分离率较低,主要流行的金属酶基因型为VIM-2型, 其基因盒散布在位于染色体上的不同整合子中。更多还原

【Abstract】 Objective To demonstrate the genotyping and the transmission mechanism of imipenem-resistant Pseudomonas aeruginosa (IRPA).in part of China. Methods: The 140 imipenem-resistant Pseudomonas aeruginosa isolates were collected from hospitals in five different regions throughout China. The minimal inhibitive concentrations (MICs) of antimicrobial agents to these strains were determined by Etest and agar dilution method. MBL producers were detected by Screening tests. PCR assays were performed to amplify the sequences of the MBL and integron gene. Pulsed-field gel lectrophoresis (PFGE) was used to analyze the homology of the strains. Conjugation experiment, Southern hybridization, plasmid extraction and electrotransformation were carried out for the location of MBL genes. Results: Twelve strains were detected producing metallo-β-lactamases by disk diffusion test. However, 14 strains were detected metallo-β-lactamases VIM-2 positive by PCR. Two kinds integron were detected from 12 of the 14 P. aeruginosa, containing aacA4, blaVIM-2 and aacA4, blaVIM-2, aadB, respectively. Repeated attempts to transfer the MBL gene by conjugation and electrotransformation were both failed. Seven different PFGE types were found among 14 strains. The VIM-2 probe hybridized with the 50-kbp XbaI fragment by Southern hybridization. Conclusions: The prevalence of MBL-producing strains among imipenem resistance P. aeruginosa isolates from five different regions throughout China was lower. MBL production was not the main reason for imipenem resistance of the strains. VIM-2 was the main MBL type. The blaVIM-2 gene cassette has disseminated among various class 1 integrons.更多还原