摘要
目的 通过对90株多重耐药革兰阴性菌携带的整合子及耐药基因盒类型的检测,探讨整合子、基因盒与耐药表型的相关性.方法 采用PCR法扩增90株革兰阴性菌Ⅰ、Ⅱ、Ⅲ类整合子及整合子阳性菌株的可变区,测序分析整合子可变区耐药基因盒的类型;药敏试验检测整合子阳性菌株与阴性菌株的耐药率.结果 90株多重耐药革兰阴性菌中整合子检出率为81.1％ （73/90）,其中有Ⅰ类整合子70株,Ⅱ类整合子3株,未检测出Ⅲ类整合子.Ⅰ类整合子可变区扩增片段介于730 ～ 3300 bp,GenBank数据库BLAST分析,检测到8种整合子基因盒谱,分别为aadB 11株、aac（6’）-Ⅱ7株、aadA5 10株、dfrA17-aadA5 14株、dfrA12-OrfF-aadA2 1株、aacA4-catB8-aadA1 24株、aacC1-OrfA-OrfB-aadA1 3株与catB3-aadB-dhfrV-aacA4-nit-nit2 1株,其中catB3-aadB-dhfrV-aacA4-nit1-nit2是一种新型的耐药基因盒组合形式;Ⅱ类整合子可变区片段为1600 bp,3株均携带sat2-aadA1基因盒.药敏试验表明整合子阳性菌株对氨基糖苷类和磺胺类药物耐药率高,与整合子可变区耐药基因盒的结果相符;阳性菌株对阿米卡星较为敏感,耐药率为32.9％（24/73）;另外所有菌株对多数β-内酰胺酶类药物耐药率≥80％.结论 多重耐药革兰阴性菌Ⅰ类整合子携带率较高,且菌株耐药表型与其整合子可变区耐药基因盒的类型有相关性.
Objective To explore the correlations of integrons,gene cassettes and drug resistance phenotypes in 90 multi-drug resistant Gram-negative bacteria.Methods Class Ⅰ/Ⅱ/Ⅲ integron and variable region of positive strains of 90 Gram-negative bacteria were amplified by PCR and types of integron variable region gene cassettes analyzed by DNA sequence.And the resistant rates of integron positive and negative strains were tested by drug susceptibility.Results The detection rate of integron was 81.1% （73/ 90） in 90 Gram-negative bacteria.The integron types were class Ⅰ （n =70）,class Ⅱ （n =3） and class Ⅲ （n =0）.Based on the BLAST analysis by GenBank database,in the amplified fragments of Class Ⅰ integron positive strains variable region gene ranging from 730 to 3300 bp,8 types of integron structure were identified.And there were aadB （n =11）,aac （6＇）-Ⅱ （n =7）,aadA5 （n =10）,dfrA17-aadA5 （n =14）,dfrA12-OrfF-aadA2 （n =1）,aacA4-catB8-aadA1 （n =24）,aacCl-OrfA-OrfB-aadA1 （n =3）,catB3-aadB-dhfrV-aacA4-nit1-nit2 （n =1）,inwhich catB3-aadB-dhfrV-aacA4-nit1-nit2 was a new resistance gene cassette; the variable region fragment of class Ⅱ integron positive strain was 1600 bp,with 3 carrier strains of sat2-aadA1 gene cassette.Susceptibility testing showed that the antimicrobial resistance rate of integron positive strains to aminoglycosides and sulfa were significantly higher than those of integron negative strains and accorded with the results of integration variable region gene cassettes; the positive strains were more sensitive to amikacin with a resistance rate of 32.9% （24/73） ; and the drug resistance rates of all betalactam strains were ≥ 80%.Conclusions There is a higher carrier rates of class Ⅰ integron in Gramnegative bacteria.And the resistant phenotype is related with the types of resistance gene cassettes of integron variable region.
出处
《中华医学杂志》
CAS
CSCD
北大核心
2013年第46期3698-3702,共5页
National Medical Journal of China
关键词
抗药性
多药
革兰氏阴性菌
整合子类
耐药基因盒
Drug resistance, multiple
Gram-negative bacteria
Integrons
Resistance genecassette
