Molecular Identification of Vibrio harveyi From Larval Stage of Pacific White Shrimp (Litopenaeus vannamei) Boone (Crustacea:Decapoda)By Polymerase Chain Reaction and ۱۶S rDNA Sequencing

A Gram-negative, rod-shaped, motile and halophilic bacterium identified as Vibrio harveyi was isolated from hatchery-reared larval of Iran Shrimp Research Centerfollowing mass mortality . Seven isolates of Vibrio spp.were collected from nauplii of Litopenaeus vannamei and then were evaluated for characteristics including morphology, physiology and biochemistry. The results indicated that the isolates belonged to a single species that grew on Thiosulfate citrate- Bile Sucrose agar and in ۱.۵ to ۶% NaCl, positive lysine and ornithine decarboxylation and susceptible to O/۱۲۹ disk. Identification of Vibrio harveyi strainIS۰۱ (۱ of ۷ isolates) was confirmed by Polymerase Chain Reaction assay for Vibrio harveyi (expected amplicon ۱۴۹۳ bp). The ۱۶S ribosomal DNA sequence (National Center for Biotechnology Information, GenBank accession number GU۹۷۴۳۴۲.۱) gave ۹۹% sequence identity to V. harveyi ATCC: ۳۵۰۸۴ (GenBank accession number EU۱۳۰۴۷۵.۱).

Keywords:

Vibriosis , shrimp diseases , Litopenaeus vannamei , ۱۶S rDNA sequencing