Detection of virulence genes in vibrio alginolyticus isolated from green mussel, perna viridis

Abstract

Vibrio sp. is known as pathogenic microorganism affecting aquatic species. They are commonly isolated from wild fish, mollusc and bivalves. V. alginolyticus carries several virulence genes such as ompK, toxR and collagenase that can cause severe infection to the fishes, crustaceans and bivalve mollusks. Therefore, this study was carried out to detect the presence of virulence genes from V. alginolyticus isolated from mantle, adductor muscle, gill, hemolymph, gastrointestinal tract of infected green mussels; including from the water and rope of the cultivation areas. Further identification of the isolates was carried out using conventional method and 16S rDNA sequence analysis. The detection of virulence genes, namely ompK, toxR and collagenase were carried out using gene-targeted PCR method. A total of 21 isolates were confirmed as V. alginolyticus. Results showed that 67% of the isolates carry ompK, toxR and collagenase genes, while 19% carry both ompK and toxR genes. Only 5% from the total isolates carried the ompK and collagenase genes while 10% of the isolates carried ompK gene only. Overall, the results indicated that most of V. alginolyticus isolates are pathogenic bacteria as they carried the virulence factor.