Complete genome sequence analyses of an Indian cattle strain of bovine viral diarrhoea virus 2 (BVDV-2)

Bovine viral diarrhea virus (BVDV) is a pestivirus which infects cattle worldwide causing substantial economic losses in cattle farming. BVDV is divided into two recognized species, BVDV-1 and BVDV-2 and one tentative species, BVDV-3. Since, complete genome sequence analysis can provide better insights into molecular epidemiology of BVD, we report here the first complete genome sequence analyses of an Indian BVDV-2 strain isolated from cattle. The full-genome of strain Ind 141353 contains 12285 nucleotides (nt) with a single large open reading frame which codes for 3898 amino acids. Phylogenetic analysis indicated that this strain belongs to the BVDV-2a subtype and has highest (93%) level of genetic identity with the Chinese cattle strain JZ05-1. It was inferred that although introduction from China is possible, introduction of BVDV-2 into Indian and Chinese cattle from a common trade source cannot be ruled out completely. The results in this study extend the spectrum of pestivirus molecular data and provide important insights into BVDV molecular epidemiology.

siRNAs targeting PB2 and NP genes potentially inhibit replication of Highly Pathogenic H5N1 Avian Influenza Virus.

Highly Pathogenic Avian Influenza (HPAI) H5N1 virus is a threat to animal and public health worldwide. Till date, the H5N1 virus has claimed 402 human lives, with a mortality rate of 58% and has caused the death or culling of millions of poultry since 2003. In this study, we have designed three siRNAs (PB2-2235, PB2-479 and NP-865) targeting PB2 and NP genes of avian influenza virus and evaluated their potential, measured by hemagglutination (HA), plaque reduction and Real time RT-PCR assay, in inhibiting H5N1 virus (A/chicken/Navapur/7972/2006) replication in MDCK cells. The siRNAs caused 8- to 16-fold reduction in virus HA titers at 24 h after challenged with 100TCID50 of virus. Among these siRNAs, PB2-2235 offered the highest inhibition of virus replication with 16-fold reduction in virus HA titer, 80% reduction in viral plaque counts and 94% inhibition in expression of specific RNA at 24 h. The other two siRNAs had 68–73% and 87–88% reduction in viral plaque counts and RNA copy number, respectively. The effect of siRNA on H5N1 virus replication continued till 48h (maximum observation period). These findings suggest that PB2-2235 could efficiently inhibit HPAI H5N1 virus replication.