Genetic diversity of infectious pancreatic necrosis virus (IPNV) in farmed rainbow trout (Oncorhynchus mykiss) in Iran

Infectious pancreatic necrosis (IPN) is one of the most important viral diseases in the aquaculture industry. This study aimed to determine the genetic diversity of infectious pancreatic necrosis virus (IPNV) isolated from farmed rainbow trout in Iran during 2011 to 2013 using VP2 gene sequencing. Trout larvae and fingerlings (200 mg-1.5 g) undergoing IPN outbreaks were collected from fish farms and IPNV was detected by reverse-transcription polymerase chain reaction (RT-PCR). In addition, samples of ovarian and seminal fluids were obtained from brood fish and screened for IPNV by RT-PCR. After RT-PCR characterization of the viral isolates, a 205 bp portion of the IPNV VP2 gene were sequenced to determine the genetic diversity of the viral strains detected in Iran. The phylogenetic analysis of the 40 IPNV strains showed that these isolates can be grouped into 6 genogroups. All isolates except genogroup one showed a high genetic similarity (96.57%).