Phylogenetic analysis of viral hemorrhagic septicemia virus from recent outbreaks in some of the Iranian farmed rainbow trout Oncorhynchus mykiss (Walbaum, 1792)

Abstract

<br /> During a fish disease outbreaks in 2015-2016 suspected to viral hemorrhagic septicemia virus (VHSV), moribund rainbow trout fries were obtained from fish farms. Samples of kidney, heart and spleen tissues were taken [X1] for examination. The full coding region of the G gene was amplified by RT-PCR reaction. Genotyping was carried out by phylogenetic analysis with reference sequences of four VHS genogroup. A phylogenetic tree was constructed with the maximum likelihood method and the Kumara 2- parameter substitution model by using MEGA software version 6.06. A maximum likelihood phylogenetic analysis reveals that all the Iranian VHS strains belonged to clade Ia-2 of genotype Ia. The intra- sequence comparison of Iranian VHS strains ranged from 99.1% to 100% (average was 99.55%). In this study, two strains (Chaharmahal and Bakhtiari (1) and Chaharmahal and Bakhtiari (3) showed 100% identity but 0.1% differences with Isfahan strain. The Iranian strains belonging to European genogroup are related (99% identity) to VHSV from recent Italian strains (VHSV/O.mykiss/I/TN/133/Apr10).<br /> <br /> <br /> <br /> [X1]نیازی به ماضی نقلی نیست ، مجهول گذشته ساده صحیح است.