西安市细菌性腹泻病原菌分子分型及耐药性分析

Molecular typing and analysis of the drug resistance of pathogenic strains causing bacterial diarrhea in the City of Xi'an

目的了解西安市腹泻病原菌株耐药性变迁及分子分型特征。方法收集2005-2016年西安市腹泻病监测、食物中毒及食品风险监测中分离的沙门菌127株,志贺菌79株,采用VITEK-Compact AST GN13革兰阴性菌药敏鉴定卡进行MIC值检测,并用18种抗生素做药敏试验;采用PFGE(脉冲场凝胶电泳)进行分子分型,使用PulseNet软件进行聚类分析。结果 127株志贺菌对氨苄西林、氨苄青霉素/舒巴坦耐药率分别为90.55%和80.31%,对磺胺类药物耐药率87.4%,对头孢一、二代及氨基糖苷类药物完全耐药,对碳青霉烯类和单环内酰胺类药物完全敏感,对部分头孢三、四代及氟喹诺酮类药物耐药率较低;79株沙门菌对氨苄西林、氨苄青霉素/舒巴坦耐药率分别为50.49%和50.63%,对头孢一、二代及氨基糖苷类药物完全耐药,对部分头孢三、四代、单环内酰胺类,磺胺类及氟喹诺酮类药物耐药率较低,对碳青霉烯类药物耐药率为1.66%,并存在5重及以上耐药株,PFGE检测75株宋内志贺菌和79株沙门菌均出现67种不同带型,51株福氏志贺菌出现44种不同带型。结论西安市2005-2016年所分离的沙门菌和志贺菌多重耐药严重,PFGE带型呈遗传多态性。

Objectives To investigate changes in the drug resistance of pathogens causing diarrhea in Xi’an and to molecularly type those pathogens. Methods From 2005 to 2016,127 strains of Salmonella and 79 strains of Shigella were collected from surveillance of diarrhea and food poisoning and food risks in the City of Xi’an.MIC values were determined with the VITEK-Compact AST GN13 card for identification of Gram-negative bacilli.A drug sensitivity test was performed with 18 antibiotics.Molecular typing was performed using pulsed field gel electrophoresis(PFGE),and cluster analysis was performed using the software PulseNet. Results The resistance of 127 Shigella strains to ampicillin was90.55% and their resistance to ampicillin/sulbactam was 80.31%.The strains were fully sensitive to carbapenems and monocyclic lactams and had low resistance to some of the third-and fourth-generation cephalosporins and fluoroquinolones.The resistance of 79 Salmonellastrains to ampicillin was 50.49% and their resistance to ampicillin/sulbactam was50.63%.Their resistance to amines and fluoroquinolones was low and their resistance to carbapenem was 1.66%.At least 5strains were resistant.Seventy-five strains of S.sonnei and 79 strains of Salmonella produced 67 different bands in PFGE.Fifty-one of S.flexneri produced 44 different bands. Conclusion The strains of Salmonellaand Shigellaisolated in Xi’an from 2005 to 2016were highly multidrug-resistant,and bands in PFGE revealed genetic polymorphism.