贵阳地区儿童幽门螺杆菌临床分离菌株毒力基因cagA和vacA的表达情况以及与抗生素耐药之间的关系

Expression of virulence genes cagA and vacA of Helicobacter pylori clinical isolates in Guiyang region and relationship between antibiotic resistance and the virulence genes

目的分析贵阳地区儿童幽门螺杆菌临床分离菌株的毒力基因cagA和vacA的表达情况,以及探讨其和幽门螺杆菌耐药之间的关系。方法从有上消化道症状的患儿的的胃窦粘膜中分离培养出幽门螺杆菌31株,采用聚合酶链式反应检测cagA和vacA的分布情况。用琼脂稀释法检测幽门螺杆菌对阿莫西林、克拉霉素、甲硝唑和左氧氟沙星的耐药性。结果本地区儿童幽门螺杆菌的cagA基因的阳性率为83.87%。vacA基因亚型s1a、s1b、s1c、m1和m2的检出率分别为83.87%(26/31)、0%(0/31)、19.35%(6/31)、12.90%(4/31)和74.19%(23/31)。优势基因为vacAs1am2型。毒力基因与不同的疾病之间无相关性。cagA基因和vacA基因与阿莫西林、克拉霉素、甲硝唑及左氧氟沙星耐药无相关性(P>0.05)。结论贵阳地区儿童的毒力基因cagA+和vacAs1m2型为主。毒力基因与抗生素的耐药性之间无相关性。

Objective To evaluate the expression of virulence genes cagA and vacA of Helicobacter pylori clinical isolates and the prevalence of drug resistance in children in Guiyang and to investigate whether there was any rela-tionship between genotype and drug resistance in this study.Method Thirty-one Helicobacter pylori were isolated from patients with upper gastrointestinal diseases.Polymerase chain reaction assays were used for the determination of virulence factors.Antimicrobial susceptibility was tested by Agar dilution method.Result The positive rate of cagA was 83.87% in this aera.Of those31 specimens ,83.87% ,0% ,19.35% ,12.90% and 74.19% carried vacAs1a ,va-cAs1b ,vacAs1c ,vacAm1 ,and vacAm2 ,respectively.The resistance rates to amoxicilin ,clarithromycin ,metronidazole and levofloxacin were 16.13% （5/31） ,19.35% （6/31） ,41.94% （13/31）and 12.90% （4/31） ,respectively.There were no relationship between cagA and vacA genotype and antibotic resistance.Conclusion Dominant genotype was cagA＋vacAs1am2.