副溶血弧菌(Vibrio parahaemolyticus)中溶源噬菌体与其宿主菌致病力的相关性

Isolation of Lysogenic Phage in Vibrio parahaemolyticus and Its Relationship with the Pathogenicity of the Host Bacteria

中文关键词: 副溶血弧菌  溶源噬菌体  急性肝胰腺坏死病

英文关键词: Vibrio parahaemolyticus  Lysogenic phage  Acute Hepatopancreatic Necrosis Disease (AHPND)

中文摘要:

      急性肝胰腺坏死病(Acute Hepatopancreatic Necrosis Disease, AHPND)是由副溶血弧菌(Vibrio parahaemolyticus)引起的对虾病害，本研究从患AHPND的凡纳滨对虾样品中分离得到5株副溶血弧菌，采用致AHPND的副溶血弧菌(VPAHPND)的相关质粒的引物AP2进行PCR检测，表明这5株菌中均存在AHPND相关质粒。利用丝裂霉素C进行溶源性噬菌体筛选和噬菌体诱导发现，其中2株副溶血弧菌(20130629002S01和20130726001S01)可能存在溶源性噬菌体感染；从经0.5 μg/ml丝裂霉素C诱导的20130629002S01和20130726001S01中分别分离得到两种噬菌体phage1和phage2。透射电镜观测显示，phage1为有尾噬菌体，phage2为球形噬菌体。将上述5株副溶血弧菌进行卤虫无节幼体人工感染实验，结果显示，它们对卤虫无节幼体均有致病力，且各分离株的毒力表现出显著性差异；20130629002S01和20130726001S01两株带有溶源性噬菌体的副溶血弧菌的致病力显著低于无噬菌体的副溶血弧菌(20130721001S02)。本研究结果表明，5株VPAHPND分离株都含有AHPND相关的质粒，表现出显著的毒力差异，可能携带不同的溶源噬菌体，也可能不携带溶源噬菌体，溶源噬菌体与副溶血弧菌各分离株的毒力并无必然相关性。

英文摘要:

      Acute hepatopancreatic necrosis disease (AHPND) is caused by infection with Vibrio parahaemolyticus. In this study, five strains of V. parahaemolyticus were isolated from Litopenaeus vannamei with AHPND. The primer set AP2 targeting the plasmid harbored in AHPND-causing V. parahaemolyticus (VPAHPND) was used in the PCR amplification, and it was found that all five isolates carried the AHPND related plasmid. Mitomycin C was used to induce and screen the lysogenic phages in VPAHPND isolates. The growth curves showed that two isolates of V. parahaemolyticus, 20130629002S01 and 20130726001S01, contained lysogenic phages. Phage 1 and Phage 2 were released from 20130629002S01 and 20130726001S01 respectively after the induction with 0.5 μg/ml mitomycin C. Transmission electron microscopy revealed that Phage 1 had a tailed shape and Phage 2 had a spherical shape. The challenge test on Artimia nauplii suggested that the virulence was significantly different between the 5 strains of V. parahaemolyticus. The pathogenicity of two lysogenic phages-containing strains, 20130629002S01 and 20130726001S01, was significantly lower than that of phage-free 20130721001S02. Our study suggested that the presence of lysogenic phage might not necessarily correlate with the pathogenicity of the host bacterium V. parahaemolyticus.