Characterization of Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease in southern Thailand          下载免费PDF全文

J Kongrueng  M Yingkajorn  S Bunpa  N Sermwittayawong  K Singkhamanan  V Vuddhakul 《Journal of fish diseases》2015,38(11):957-966

Vibrio parahaemolyticus was isolated from shrimp of five farms located in the Pattani and Songkhla provinces of southern Thailand. Using a PCR method targeted to the unique DNA sequences derived from the plasmid (AP2 primers) and the toxin gene (AP3 primers) of V. parahaemolyticus that caused acute hepatopancreatic necrosis disease (AHPND), a total of 33 of 108 isolates were positive. In contrast, all 63 and 66 isolates of clinical and environmental V. parahaemolyticus, respectively, obtained previously from 2008 to 2014 from the same area were negative. This implied that these strains were likely to be the cause of the outbreak of AHPND in this area. Intestinal samples proved to be a better source for the isolation of V. parahaemolyticus AHPND than the hepatopancreas. All isolates were investigated for haemolytic activity, virulence genes, serotypes, genotypes and antibiotic susceptibility. All the AHPND isolates had a unique O antigen, but small variations of the K antigens were detected from different farms. In addition, the DNA profiles of V. parahaemolyticus AHPND isolates were similar, but distinct from those clinical and environmental isolates. It is postulated that the causative agent of AHPND might have originated from one clone and then slightly different serotypes subsequently developed.  相似文献   

Outer membrane protein A (OmpA) is a potential virulence factor of Vibrio alginolyticus strains isolated from diseased fish     

Supansa Bunpa  Nattarika Chaichana  Jade L. L. Teng  Hwei Huih Lee  Patrick C. Y. Woo  Decha Sermwittayawong  Nongyao Sawangjaroen  Natthawan Sermwittayawong 《Journal of fish diseases》2020,43(2):275-284

Vibrio alginolyticus is one of the most serious causative agents of diseases in cultured marine fish and shellfish. However, the characteristics of virulence factors in pathogenic V. alginolyticus are poorly known. To gain insight into fish diseases caused by V. alginolyticus, we carried out two-dimensional gel electrophoresis (2-DE) combined with MALDI-TOF mass spectrometry to identify uniquely expressed proteins in the disease-causing V. alginolyticus. V. alginolyticus strains were isolated from marine environments and diseased fish obtained from southern Thailand. We identified seven unique proteins in the disease-causing V. alginolyticus strain. Among those, the outer membrane protein A (OmpA) had the strongest expression. Therefore, the function of this protein was further analysed. To investigate the role of OmpA protein, an in-frame deletion mutant of ompA was constructed using the homologous recombination method. Although the ompA mutant V. alginolyticus strain (ΔompA) grew normally, the mutant exhibited a significant defect in the swarming ability and the biofilm formation. Furthermore, Galleria mellonella larvae injected with the mutant bacteria had a significantly greater survival percentage than those injected with the wild-type strain, demonstrating that OmpA protein is required for the pathogenicity of V. alginolyticus. Together, this study suggests a potential target for vaccine development against pathogenic V. alginolyticus strain.  相似文献