Background: Infectious pancreatic necrosis virus (IPNV), a member of
the virus family Birnaviridae, causes an acute, contagious disease with
high mortality rate in a number of economically important fi sh species
specially salmonids. During April 2009, one Rainbow trout farm, situated
in Gilan province, north of Iran, reported unusually high losses of reared
rainbow trout fry with average weight of 560 mg. same mortality were
reported from 4 other farms in fryes under 1 gram weight in 2010. Clinical
signs included darkening, exophthalmia, distended abdomen, fecal cast
and a spiral swimming motion. Cumulative mortalities were more than
90%. Water temperature was between 12 to 16°C. Alive affected fi sh were
delivered to the virology laboratory of Inland water aquaculture institute
situated in Bandar anzali for diagnostic investigation. Clinical signs,
mortality levels, age and size of fi sh and necropsy fi ndings suggested
that IPNV might be present. The presence of virus was confi rmed by
virology methods with cooperation of community reference laboratory of
fi sh disease, Arhus,Denmark.
Methods and Materials: Pools of viscera from each fi ve whole fry were
homogenized, re-suspended in medium and clarifi ed by centrifugation
at 2000 rpm for 20 minutes in 4°C. Supernatants were inoculated onto
monolayers of the BF-2 and EPC cell lines in 24 well multidishes and
identifi ed by ELISA, IFAT, NT, Nested-RT-PCR and Chloroform test. The
PCR product of an isolate was sequenced and the Phylogenic tree was
constructed from the sequencing data.
Results: CPE was observed 24h post inoculation and IPNV identifi ed
by ELISA, IFAT, Nested-RT-PCR and Chloroform test. In neutralization
test, the virus showed more closely relationship to the SP (A2) serotype.
Through an analysis including to other polyprotein gene sequences
deposited in Genbank, a Spanish isolate ( ATCC AJ489222.1) was found
more similar to Iranian isolate.
Conclusion: Serotype of aquabirnavirus isolated in this study
suggesting that the original source of the virus was in Europe. This is the
fi rst isolation and identifi cation of IPN virus from rainbow trout fry in Iran.
|Conference||IMED 2011 International Meeting on Emerging Diseases and Surveillance|
|Period||04/02/2011 → 07/02/2011|
- Rainbow trout