阿贡纳沙门菌引起的聚集性腹泻病例监测及分析

目的 应用脉冲场凝胶电泳(pulsed-field gel electrophoresis,PFGE)分子分型技术分析时间上高度集中的散发腹泻病例,发现可能的聚集性,并进行流行病学调查和追溯。 方法 利用已建立的北京市肠道多病原分子分型监测系统,采集腹泻病例粪便标本进行病原菌分离培养、生化鉴定、血清凝集、药敏试验及PFGE分子分型。 结果 2012年5月2-7日连续一周内,从北京市某区(县)肠道门诊采集的22份腹泻病例粪便标本中分离到9株沙门菌,血清学鉴定为阿贡纳沙门菌。XbaⅠ 酶切的PFGE带型一致,与中国细菌性传染病分子分型实验室监测网络(PulseNet China)中心数据库及各地区网络实验室数据比对分析后,确认该带型为一新的图谱带型,编码为JABX01.CN0072。 结论 9 例阿贡纳沙门菌感染病例的发病时间和地理分布高度集中,且PFGE带型聚集成簇,提示感染菌株具有同一克隆来源。随后的流行病学调查和感染来源分析,虽并未发现共同暴露因素,但说明PFGE技术的应用可以提高监测的敏感性,应长期持续的进行病原菌分子分型监测,进一步完善PulseNet网络和运行机制。

Surveillance of diarrhea case cluster caused by Salmonella Agona

Objective To find out the possible clustering of sporadic diarrhea cases occurred in same period by using pulse field gel electrophoresis assay and conduct epidemiological survey and tracing. Methods Through PulseNet established in Beijing, the stool samples were collected from diarrhea patients to conduct pathogen isolation, biochemical identification, serotyping, drug susceptibility test and PFGE subtyping. Results From 2 to 7 May 2012,9 strains of Salmonella Agona were isolated from 22 stool samples of intestinal outpatients in a district in Beijing. The 9 strains of S. Agona showed same PFGE pattern by XbaⅠ enzyme digestion. In comparison with PulseNet China central database and local network laboratory database, the pattern was confirmed as a new type, encoded as JABX01.CN0072. Conclusion It suggested that 9 S. Agona isolates might be from same clone considering the highly concentrated infection time and place distribution of the cases and the clustering of PFGE pattern. Although common exposure factors were not found by the subsequent epidemiological survey and analysis of infection source, PFGE subtyping can improve the sensitivity of the surveillance. It is necessary to conduct consecutive molecular typing surveillance of pathogens and further improve PulseNet system and operation mechanism.