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目的了解杭州地区2000-2002年副溶血弧菌临床和环境分离菌株的分子流行病学特征。方法对172株2000年和2002年从临床食物中毒患者和散发腹泻病例以及外环境(小水产品)中分离的副溶血弧菌菌株进行血清分型。对40株临床来源O3:K6型菌株及环境来源O3:KUT (K抗原未分型)型菌株,应用PCR技术进行耐热直接溶血素基因(tdh)和耐热直接溶血素相关基因 (trh)的检测,并进行核糖体基因分型(ribotyping)、随机扩增多态性DNA分析(RAPD)、肠道细菌重复基因间共同序列PCR(ERIC-PCR)等。结果在调查的13起副溶血弧菌引起的食物中毒中,tdh 阳性、trh阴性的O3:K6血清型引起的有11起(84．6％);tdh阳性、trh阴性的O4:K8菌引起有2起 (15．4％)。在散发腹泻病例中,tdh阳性、trh阴性的O3:K6、O4:K8和O1:KUT菌株分别占26．5％(9／ 34)、17．6％(6／34)和38．2％(13／34),未能分型的占17．6％(6／34)。在水产品中分离的菌株中,37株分属7种O血清型,其中未见有O3:K6和O4:K8血清型;另外有9株未能分型;其中除1株O1:KUT 菌株trh阳性外,其余tdh和trh均为阴性。绝大部分食物中毒患者和散发腹泻病例分离的O3:K6菌株在ribotyping、ERIC-PCR及RAPD三种指纹上均属于一种密切相关的克隆群,而环境分离的 O3:KUT菌株与临床分离的O3:K6菌株间,在三者指纹上均有明显差异。结论临床来源和小水产品来源的副溶血弧菌菌株间血清型分布有显著差别;一群关系密切、tdh阳性、trh阴性的O3:K6血清型菌株在杭州地区呈优势流行。
Objective To investigate the molecular epidemiological characteristics of clinical and environmental isolates of Vibrio parahaemolyticus from 2000 to 2002 in Hangzhou area. Methods Serotypes of 172 isolates of Vibrio parahaemolyticus isolated from clinical food poisoning patients and diarrheal cases and from the external environment (small aquatic products) in 2000 and 2002 were serotyped. Forty (40) O3: K6 strains of clinical origin and O3: KUT (non-typed K strain) strains from clinical sources were used to detect the expression of heat-resistant direct hemolysin (tdh) and heat-resistant hemolysin related genes (Ribotyping), random amplified polymorphic DNA analysis (RAPD), intestine bacterial repeat intergenic sequence PCR (ERIC-PCR) and so on. Results Of the 13 food poisonings caused by V. parahaemolyticus investigated, 11 (84.6%) were caused by tdh-positive and trh-negative O3: K6 serotypes; tdh-positive and trh-negative by O4: K8 There are 2 (15.4%). Among diarrhea cases, tdh positive, trh negative O3: K6, O4: K8 and O1: KUT strains accounted for 26.5% (9/34), 17.6% (6/34) and 38.2% (13/34), failed to type accounted for 17.6% (6/34). Of the isolates isolated from aquatic products, 37 isolates belonged to 7 serogroup O serogroups, of which serogroup O3: K6 and O4: K8 were not found; 9 isolates could not be typed; among them, 1 strain except O1: KUT trh positive, the rest of tdh and trh were negative. Most O3: K6 strains isolated from patients with food poisoning and diarrhea cases belong to a closely related group of clones on ribotyping, ERIC-PCR and RAPD fingerprinting, whereas the environmentally isolated O3: KUT strains are clinically isolated O3: K6 strains, there are significant differences in the three fingerprints. Conclusion There are significant differences in the distribution of serotypes among clinical isolates and strains of Vibrio parahaemolyticus. A group of closely related, tdh-positive and trh-negative serotypes of O3: K6 are prevalent in Hangzhou.