北京市密云地区沙门菌喹诺酮耐药分子机制及同源性分析

Analysis of molecular homology and molecular mechanisms of Quinolones resistance of Salmonella in Miyun district of Beijing

目的了解北京市密云地区沙门菌的耐药特点和分子机制,并进行同源性分析。为沙门菌感染食源性疾病的防控提供科学依据。方法 2015年分离食源性疾患患者的沙门菌共28株,进行血清学鉴定和体外药敏试验,采用PCR扩增沙门菌的喹诺酮耐药区(QRDRs)基因(gyr A、gyr B、par C和par E),用脉冲场凝胶电泳(PFGE)检测菌株间的分子同源性。结果 2015年密云地区沙门菌感染主要以鼠伤寒沙门菌和都柏林沙门菌为主,通过PFGE图谱分型并聚类分析,分别分成7种和5种型别,喹诺酮耐药率最高,并以87位Asp→Tyr/Asn/Gly突变为主。结论密云地区食源性疾患患者沙门菌可能存在暴发,临床需谨慎使用喹诺酮类药物治疗沙门菌食源性疾患感染。

Objective To investigate the molecular mechanisms of antimicrobial resistance and analyze genetic homogeny of Salmonella in Miyun district of Beijing,to provide a scientific basis for Salmonella prevention and control. Methods A total of28 Salmonella strains were isolated from diarrhea patients in 2015,following serum typing test and antimicrobial susceptibility test. PCR were used to investigate the mutation in QRDR of the gyr A,gyr B,par C and par E. Molecular homology of all isolates were typed by pulsed- field gel electrophoresis（ PFGE）. Results Salmonella typhimurium and Salmonella dublin were the most common serotypes with 7 different clusters and 5 clusters by PFGE. Quinolone resistance rate was the most highest and the main mutation was at the site of 87 rd amino acid Asp→Tyr / Asn / Gly. Conclusion Salmonella serotypes in diarrhea patients in Miyun may broke out. Clinical should be cautious to use quinolone for Salmonella infection.