贝类水产中副溶血性弧菌菌型分布研究

目的了解贝类水产中副溶血性弧菌(VP)的菌型构成及其特点。方法按照GB/T 4789.7标准处理贝类标本,每份VP阳性标本挑取10个克隆,并对其进行血清分型,以PCR法检测tdh、trh、GS-PCR和f237噬菌体的携带情况,并据此对阳性标本中的VP进行菌型区分,分析各菌型在相应标本中的构成。结果 75份贝类水产中18份(24.0%)检出VP,5.6%携带trh阳性VP(O4∶KUT),未检出tdh阳性菌株。18份VP阳性标本共获得180株VP克隆,共可分为42种菌型。检出3株O3∶K6和1株O1∶K33 GS-PCR阳性菌株,均为非流行株。不同标本中菌型数不完全相同,最多可检出9种,平均每份VP阳性标本含6.1种菌型。检出47个(26.1%)克隆株携带f237的orf8完全缺失变种。结论 f237 orf8完全缺失变种噬菌体在贝类中具有广泛的分布。贝类中VP种群构成复杂,常携带多个菌型。临床常见菌型在贝类中不具优势,食品中VP的检测应充分考虑血清分型、基因分型的作用。

Investigation of diversity of Vibrio parahaemolyticus in molluscs

Objective To understand the serotypes of Vibrio parahaemolyticus in mollusks. Methods Molluscs samples were treated according to GB/T 4789.7. Ten V. parahaemolyticus colonies were picked up from each positive sample and their serotypes were detected. PCR was conducted to detect tdh, trh, GS-PCR and phage f237. Results In 75 molluscs samples, 24. 0% were contaminated with V. parahaemolyticus, and 5.6% of V. parahaemolyticus strains were trh positive, no tdh positive strains were detected. A total of 180 colonies of V. parahaemolyticus were obtained from 18 positive molluscs samples, which could be classified into 42 serotypes. Three 03：K6 strain and 1 O1：K33 strain were detected, but they didn＇t belonged to circulating strain. The serotype number varied with samples, the highest was 9 and the average was 6. 1. Variants of phage f237 with orf8 complete deletion were detected in 47 （26. 1% ） colonies. Conclusion Variant of phage f237 with orf8 complete deletion was widely distributed in molluscs. Molluscs is naturally contaminated with multiple types of V. parahaemolyticus. V. parahaemolyticus detected in human are rare in food, so it is necessary to conduct serotyping and genotyping in V. parahaemolyticus detection in food samples.