北部湾茅尾海副溶血性弧菌的分离鉴定与致病性分析

Isolation, Identification and Pathogenicity Analysis of Vibrio parahaemolyticus Strains from Maowei Sea, Beibu Gulf

摘要:

为解析北部湾海域及水产品中副溶血性弧菌的多样性特征与安全风险，本研究采集了北部湾茅尾海养殖区域海水和水产经济动物样品，利用硫代硫酸盐柠檬酸盐胆盐蔗糖琼脂培养基（TCBS）对所采样品进行海洋弧菌的分离和纯化，共分离获得109株疑似弧菌菌株。通过16S rDNA和特异功能基因toxR的PCR扩增并测序鉴定，共检出副溶血性弧菌20株，检出率为18.3%。此外，通过系统发育分析还发现副溶血性弧菌的toxR和tdh基因序列都存在水平基因转移现象，呈现出较大的多样性。对20个副溶血性弧菌菌株的毒力基因tdh进行分析，结果表明有4株携带了tdh毒力基因，检出率为20%，易引起食物中毒，对公共卫生造成的威胁较大。因此，本研究建议采用PCR 技术开展副溶血性弧菌特异种属基因和毒力基因检测，准确评估北部湾区域海水及其水产品的卫生安全性，降低爆发水产养殖业病害和食源性疾病的风险。

Abstract:

To analyze the diversity characteristics of V. parahaemolyticus and safety risks in sea water and aquatic products in Beibu gulf, we collected samples from seawater and aquatic economic animals in the mariculture area of Maowei sea in Beibu gulf in this study. Marine vibrio was isolated from the samples by thiosulfate citrate bile salts sucrose agar culture medium (TCBS). Totally, 109 suspected vibrio strains were obtained. A total of 20 strains of V. parahaemolyticus were identified by DNA sequencing of 16S rDNA genes and specific function gene toxR after PCR amplification. Virulence gene tdh analysis showed that 4 of the 20 strains of V. parahaemolyticus carried the virulence gene tdh, with a detection rate of 20%. In addition, phylogenetic analysis also revealed that horizontal gene transfer happened in both the toxR and tdh gene sequences of V. parahaemolyticus. The results of this study indicated that V. parahaemolyticus in Beibu gulf had high genetic diversity, and some of them carry pathogenic factors, which is a risk of outbreak of aquaculture diseases and food-borne diseases in this area. Therefore, it is suggested to use PCR technology to detect specific species genes and virulence genes of V. parahaemolyticus, accurately evaluate the health safety in seawater and aquatic products in the Beibu gulf region, and reduce the risk of outbreak of aquaculture disease and food-borne diseases.