志贺菌主动外排泵acrAB-tolC及调控基因marOR突变与耐药的关系

目的：研究志贺菌的耐药状况，检测临床分离志贺菌主动外排泵acrAB-tolC基因及调控基因marOR的突变情况，并探讨其与耐药性的关系。方法：对159株临床分离的志贺菌进行四环素、氯霉素、氨苄青霉素、庆大霉素、诺氟沙星、复方新诺明6种药物的药敏试验和有机溶剂耐受试验，对其acrAB-tolC基因和marOR基因进行聚合酶链反应（PCR）扩增，并进行限制性内切酶酶切与单链构象多态性（SSCP）分析。结果：159株临床分离的志贺菌属细菌筛选出4株敏感株、18株耐单药株和137株耐多药株，耐多药率为86.2%(137/159)；159株中有122株对有机溶剂耐受，耐受率为76.7%(122/159)；159株均扩增出acrAB-tolC基因和marOR基因，未发现基因缺失株；单链构象多态性分析，155株耐药菌株中，marOR基因的突变率为17.4%，acrA基因的突变率为5.8%，acrB基因的突变率为3.9%，tolC基因的突变率为2.6%；4株敏感株未发现marOR、acrA、acrB和tolC基因突变。结论：临床分离的志贺菌耐多药率和有机溶剂耐受率均较高，且存在较高的marOR基因突变率。

Relation of acrAB-tolC efflux pump and marOR regulated gene mutation with antimicrobial resistance in Shigella

Objective To identify the antimicrobial resistance and the mutations in acrAB-tolC efflux pump and marOR regulated genes in Shigella,then analyze their relations.Methods One hundred and fifty-nine clinical isolates of Shigella were collected.Susceptibility tests of tetracycline( TE),chloramphenicol(C),ampicillin(Am),gentamycin(GM),norfloxacin (NOR) and selectrin(SMZ-TMP) and organic-solvent tolerance test were performed in all isolates.The acrA,acrB,tolC and marOR genes of these isolates were amplified by p...