脈場膠電泳和質體輪廓法分析臺灣地區1995-1996大規模細菌性痢疾感染事件

Subspecies Typings of Shigella Isolated from Outbreaks in Taiwan, 1995-1996

本研究利用質體輪廓分析(plasmid profile analysis)和脈場膠電泳(pulsed-field gel electrophoresis, PFGE)分析臺灣地區於1995和1996年所發生之大規模細菌性痢疾(shigellosis)感染事件。以質體輪廓分析法可將15株宋內志賀菌(Shigella sonnei)分離株(isolates)區分成6型；27株副痢疾志賀菌(S. flexneri)分離菌株區分成8型。以脈場膠電泳法可將15株宋內志賀菌屬分離株區分成8型；27株副痢疾志賀菌屬分離菌株區分成14型。因而，少數質體輪廓分析呈現相同型別之分離株，可經由脈場膠電泳再加以區分。但亦有少數脈場膠電泳呈現相同型別之分離株可經由質體輪廓分析加於區別。脈場膠電泳之解析力雖優於質體輪廓分析，但結合這兩種方法於分子流行病學調查顯然比單獨使用更有效。

Shigella isolates obtained from patients are routinely identified into four species by serologic typing. Molecular typing within the same species has been established for epidemiologic studies in recent years. Plasmid profile analysis (PPA) and pulsed-field gel electrophoresis (PFGE) were used to differentiate the clinical isolates obtained from large outbreaks of Shigella infection occurring in Taiwan in 1995 and 1996. Fifteen isolates from S. sonnei and 27 isolates form S. flexneri were used in this study. Six S. sinnei and eight S. flexneri were observed using PPA, while eight S. sonnei and 14 S. flexneri were observed using PFGE. PFGE could, in 36 % (5 of 14) of the cases, further distinguish strains with the same PPA pattern. However, PPA could only occasionally further distinguish strains with the same PFGE pattern. Therefore, a combination of PFGE and PPA is preferable to PFGE alone in epidemiologic investigations of Shigella outbreaks.