菌痢暴发的分子流行病学分析

分析１９９２、１９９４年广州、江门两地菌痢暴发期间分离的８４株福氏２ａ志贺氏菌（广州暴发株３０株、散发株２８株、江门暴发株１２株、病例接触者分离株１４株）的质粒图谱及质粒ＤＮＡ限制性酶切图谱特征。结果表明：发生于不同地点、不同时间且传染来源不相同的两起菌痢暴发，由福氏２ａ志贺氏菌的同一克隆引起，该克隆可能是广东地区福氏２ａ志贺氏菌的优势克隆。江门菌痢暴发期间，自密切接触者分离的同型菌株分属３个不同的克隆，提示部分病例接触者感染的福氏２ａ志贺氏菌并非来自病例。比较表型分析（生化反应、血清学分型）与质粒分析，证实表型分析难以鉴别来源不同的同型克隆，而质粒分析提供了简便、敏感、特异鉴定不同来源同型克隆的有效手段。

Molecular Epidemiological Study on Outbreak of Shigellosis Caused by Shigella Flexneri 2a

Plasmid profiles and endonuclease restriction analysis of plasmid DNA were carried out on 84 stains of Shigella flexneri 2a (30 outbreak strains and 28 sporadic strains isolated from Guangzhou in 1992, 12 outbreak strains and 14 contacts'stains isolated from Jiangmen in 1994). The results indicated that the pathogens isolated from the two outbreaks of Shigellosis otiginated from a single clone,probably the predominate clone of S. flexneri Za in Guongdong, though the two outbreaks took place in different area, at different time and had different sources of infection. The strains isolated from contacts in Jiangmen belongs to three different clones according to their plasmid profiles and endonuclease restriction patterns,suggesting that the infection of some contacts may not come from the patients they contacted. Comparison of phenotype analysis with plasmid analysis indicated that plasmid analysis is simple,sensitive and specific for identifying sources of infection.