脉冲场凝胶电泳技术对成都市两起细菌性痢疾暴发的分型研究

Molecular typing of isolates from two dysentery outbreaks in Chengdu, through pulsed field gel electrophoresis technology

目的运用脉冲场凝胶电泳技术（PFGE）和聚合酶链反应（PCR）技术对成都市两起细菌性痢疾暴发分离株进行分析。方法利用PCR检测志贺菌分离株ipaH基因和ial基因。用PFGE对菌株进行分型，所得结果用BioNumericsV4．0软件UPGMA方法进行聚类分析。结果所试54株分离菌ipaH基因均为阳性，48株为ial阳性。以XbaⅠ酶切后PFGE分型，崇州可分为4个带型，有26株型别一致，占实验菌株（36株）的72％，为优势菌株。自凉拌白肉中分离的菌株带型与优势菌株相同。大邑县可分为8个带型，有10株型别一致，占实验菌株（18株）的56％。崇州和大邑县的优势菌株带型差异较大。结论利用PFGE能够有效地鉴别细菌性痢疾的暴发和传播来源。

Objective Using pulsed field gel electrophoresis （PFGE） and polymerase chain reaction （PCR） typing to analyze strains isolated from two outbreaks caused by Shigella sonnei and to trace the source of infection. Methods Virulence genes ipaH and ial were detected by PCR and PFGE was used to subtype the isolates. Patterns were compared, using the software BioNumerics. Results Within the 54 isolates, all were ipaH positive with 48 as ial positive. Strains from the Chongzhou outbreak were clustered into 4 PFGE patterns, with the predominant pattern accounted for 72% of the analyzed strains. The pattern of strains isolated from the cold pork with sauce was identical to the predominant pattern. The strains from Dayi outbreak were clustered into 8 PFGE patterns and the predominant pattern accounted for 56% of the test strains. Conclusion Strains from the two outbreaks were quite different and the ＇cold pork with sauce＇ seemed to be the major source of infection,causing the outbreak of diarrhea in Chongzhou. The sources of infection of the Dayi outbreak might be complicated whereas PFGE showed a discriminatory and reproducible laboratory tool in the epidemiologic investigation on outbreaks of diarrhea.