Department of Food Hygiene, College of Veterinary Medicine, Islamic Azad University, Shahr-e Kord Branch, Shahr-e Kord, Iran.
Foodborne Pathog Dis. 2010 Sep;7(9):1107-11. doi: 10.1089/fpd.2010.0554.
Vibrio parahaemolyticus, a common cause of foodborne gastroenteritis in people, is frequently isolated from a variety of seafood, including shrimp. The virulence of clinical V. parahaemolyticus strains is commonly associated with expression of thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH), which are encoded by the tdh and trh genes. This study was conducted to determine the prevalence rate of total and toxigenic V. parahaemolyticus in shrimp caught off the south coast of Iran. Three hundred freshly caught shrimp from four different species, Penaeus monodon, Penaeus semisulcatus, Penaeus indicus, and Penaeus merguiensis, were collected in three provinces along Persian Gulf in the south coast of Iran. Shrimp were collected at the end of each month from July 2008 to July 2009. The samples were analyzed for the presence of V. parahaemolyticus and the occurrence of toxigenic strains. Using conventional bacteriological techniques, 29 V. parahaemolyticus isolates were identified in which 28 strains were confirmed by a polymerase chain reaction assay targeting the tlh gene of V. parahaemolyticus. Using polymerase chain reaction assays targeting the tdh and trh genes, five (1.7%) and two (0.7%) isolates were tdh positive and trh positive, respectively. The tdh-positive isolates were commonly detected in summer, whereas no toxigenic strain was isolated in winter. To the best of our knowledge, the present study is the first report of the presence of toxigenic tdh- and trh-positive V. parahaemolyticus strains in the seafood in Iran.
副溶血性弧菌是一种常见的食源性肠胃炎病原体，常从各种海鲜中分离出来，包括虾。临床副溶血性弧菌菌株的毒力通常与耐热直接溶血素（TDH）和 TDH 相关溶血素（TRH）的表达有关，这些毒素由 tdh 和 trh 基因编码。本研究旨在确定伊朗南部沿海捕获的虾中总副溶血性弧菌和产毒副溶血性弧菌的流行率。从伊朗南部波斯湾沿岸的四个省份采集了 300 只新鲜捕获的虾，分别属于四个不同的物种，即斑节对虾、日本对虾、印度对虾和马来亚对虾。这些虾是从 2008 年 7 月至 2009 年 7 月每个月末采集的。对样品进行了副溶血性弧菌的存在和产毒菌株的检测。采用常规细菌学技术，在 29 株副溶血性弧菌分离株中鉴定出 28 株，这些分离株通过针对副溶血性弧菌 tlh 基因的聚合酶链反应（PCR）检测得到确认。采用针对 tdh 和 trh 基因的 PCR 检测，有 5（1.7%）和 2（0.7%）株分离株分别为 tdh 阳性和 trh 阳性。tdh 阳性分离株在夏季常见，而冬季未分离到产毒菌株。据我们所知，本研究是首次在伊朗海鲜中发现产毒 tdh-和 trh-阳性副溶血性弧菌的报告。
