对喹诺酮类药物耐药的志贺菌gyrA基因突变的研究

gyrA gene mutations in quinolone-resistant Shigellae flexneri

目的研究福氏志贺菌对喹诺酮类药物的耐药机制。方法对38株耐药的福氏志贺菌gyrA基因的N末端编码区进行PCR扩增后,用SSCP方法检测突变,然后测序。结果福氏志贺菌gyrA基因PCR-SSCP显示有8株突变,测序结果揭示存在2个导致氨基酸改变的基因点突变:83位TCG(Ser)→TTG(Leu)突变和87位GAC(Asp)→GGC(Gly)突变。结论gyrA基因点突变与福氏志贺菌对喹诺酮类药物的高水平耐药有密切关系。

Objective To studytheresistancemechanismof quinoloneagainstShigellae flexneri.Methods TheN-terminal codingregionof gyrA geneof38quinolone-resistantShigellae flexneri were amplifiedby PCRandmutationsdetectedby single-strandconformationpolymorphism(SSCP),followedby sequenceanalysis.Results Eightisolateswerefoundto be positivefor gyrA mutations,andDNAsequenceanalysisof gyrA generevealed2mutationsthatresultedin changesof the aminoacids(Ser-83→Leu,Asp-87→Gly).Conclusion gyrA genemutationsiscloselyrelatedto highresistanceof Shigellae flexneri toquinolone.