Complete genomic sequence of an infectious pancreatic necrosis virus isolated from rainbow trout (Oncorhynchus mykiss) in China

Abstract

Infectious pancreatic necrosis (IPN) is a significant disease of farmed salmonids resulting in direct economic losses due to high mortality in China. However, no gene sequence of any Chinese infectious pancreatic necrosis virus (IPNV) isolates was available. In the study, moribund rainbow trout fry samples were collected during an outbreak of IPN in Yunnan province of southwest China in 2013. An IPNV was isolated and tentatively named ChRtm213. We determined the full genome sequence of the IPNV ChRtm213 and compared it with previously identified IPNV sequences worldwide. The sequences of different structural and non-structural protein genes were compared to those of other aquatic birnaviruses sequenced to date. The results indicated that the complete genome sequence of ChRtm213 strain contains a segment A (3099 nucleotides) coding a polyprotein VP2-VP4-VP3, and a segment B (2789 nucleotides) coding a RNA-dependent RNA polymerase VP1. The phylogenetic analyses showed that ChRtm213 strain fell within genogroup 1, serotype A9 (Jasper), having similarities of 96.3% (segment A) and 97.3% (segment B) with the IPNV strain AM98 from Japan. The results suggest that the Chinese IPNV isolate has relative closer relationship with Japanese IPNV strains. The sequence of ChRtm213 was the first gene sequence of IPNV isolates in China. This study provided a robust reference for diagnosis and/or control of IPNV prevalent in China.

Bivalent DNA vaccine induces significant immune responses against infectious hematopoietic necrosis virus and infectious pancreatic necrosis virus in rainbow trout

“…Previous IHNV vaccines have been generated with genogroup M and U IHNV isolates 13 , 37 , 39 . The worldwide IPNV isolates consist of nine serotypes 33 , and IPNV vaccines have been developed with the Spanish IPNV strain Sp 5 , 22 , 24 , 40 , the Norwegian strain NVI015 41 , and the American VR299 strain 16 . There is no report of a vaccine developed from a Chinese IHNV or IPNV strain.…”

“…The Ja serotype of IPNV ChRtm213 33 and the J genotype IHNV Sn1203 32 are laboratory stocks. IPNV ChRtm213 was propagated in CHSE-214 cells and IHNV Sn1203 was propagated in EPC cells, as described previously 16, 51 .…”

“…Specific-pathogen-free rainbow trout (mean weight, 5 g) were maintained in 50 L tanks with circulating water at 15 °C and fed a dry pelleted diet ad libitum . The Ja serotype of IPNV ChRtm213 33 and the J genotype IHNV Sn1203 32 are laboratory stocks. IPNV ChRtm213 was propagated in CHSE-214 cells and IHNV Sn1203 was propagated in EPC cells, as described previously 16 , 51 .…”

“…Previous studies have demonstrated the co-infection of rainbow trout with IHNV and IPNV under natural conditions 30 , 31 . Therefore, in this study, a bivalent DNA vaccine was constructed with the G gene of Chinese IHNV isolate Sn1203 32 and the VP2–VP3 genes of Chinese IPNV isolate ChRtm213 33 . Here, we report the successful design and construction of this bivalent DNA vaccine, designated pCh-IHN/IPN, which induced protective immune responses against IHNV infection, IPNV infection, and co-infection with IHNV and IPNV in the rainbow trout.…”

Piscine orthoreovirus: Biology and distribution in farmed and wild fish

“…In regards to wild fish of Japan, the incidence of PRV‐2 in wild native salmon species remains unknown. In salmon and trout farming industry of China and Korea, viral diseases such as infectious haematopoietic necrosis and infectious pancreatic necrosis (Ji et al., 2017; Jia et al., 2014; Kim et al., 2007; Suebsing, Kim, Kim, Park, & Oh, 2011) have been documented; however, neither HSMI‐ nor EIBS‐like diseases have been reported from salmon of this region suggesting that if PRV is present it has not been associated with significant disease.…”