江阴地区三类整合子在多重耐药铜绿假单胞菌中的流行率及Ⅰ类整合子结构研究

目的了解2005—2006年度我院铜绿假单胞菌对几种常用抗生素的耐药率，分析我院三类整合子的流行情况；明确我院Ⅰ类整合子的基因结构。方法采用药敏纸片法检测100株铜绿假单胞菌对环丙沙星、头孢噻肟、庆大霉素和亚胺培南等的耐药率；用煮沸法提取100株铜绿假单胞菌的DNA模板；应用PCR技术检测三类整合子的流行率及其Ⅰ类整合子结构分析。结果100株铜绿假单胞菌对几种常用药物的耐药率分别为环丙沙星32％、头孢噻肟45％、庆大霉素82％、头孢西丁37％、妥布霉素39％和亚胺培南43％。三类整合子的流行率分别为Ⅰ类53％、Ⅱ类21％、Ⅲ类5％。序列分析表明，在Ⅰ类整合子可变区存在dfrA17、aadA2基因盒。结论4种药物的耐药率都有增高，以庆大霉素最显著，铜绿假单胞菌的多重耐药可能与Ⅰ类整合子的流行有重要的关系。

The prevalence rate of three species of integrons in multi-drug resistant Pseudomonas aeruginosa and investigation of class Ⅰ integron structure in Jiangyin area

Objective To investigate the resistance rate of Pseudomonas aeruginosa to several commonly used antibiotics,as well as the prevalence status of three species of integrons in multi-drug resistant Pseudomonas aeruginosa from 2005 to 2006 in our hospital,and to identify the genetic structure of class Ⅰ integron in in our hospital.Methods Drug resistance slip method was applied to detecting the resistant rates of 100 isolates of Pseudomonas aeruginosa to ciprofloxacin,cefotaxime,gentamicin and imipenem.Boiling method was adopted to abstract DNA template of 100 isolates of Pseudomonas aeruginosa,and PCR assay adopted to identify the prevalence rate of three species of integrons and class Ⅰ integron structure.Results The resistant rates of 100 isolates of Pseudomonas aeruginosa to ciprofloxacin,cefotaxime,gentamicin,cefoxitin,tobramycin and imipenem were 32%,45%,82%,37%,39% and 43% respectively.The prevalence rates of three species of integrons was as follows:class Ⅰ 53%,Ⅱ 21% and Ⅲ 5%.Sequence analysis displayed there existed box gene dfrA17 and aadA2 in variable region of class Ⅰ integron.Conclusion The resistant rates of Pseudomonas aeruginosa to four drugs are elevated,especially to gentamycin.Multi-drug resistance may be partly due to prevalence of class Ⅰ integron.