Studies on the molecular biological peculiarities of bovine herpesvirus 4

Studies on the molecular biological features of bovine herpesvirus 4 (BHV 4) strains isolated in Bulgaria have been conducted. Two types of polymerase chain reaction have been developed and applied to confirm the gB and TK genes. A restrictase fragment analysis was performed using various types of restrictase enzymes. The tested Bulgarian strains differed in their restrictase genomic profile from the reference European strain Movar 33/63 and from the American strain DN 599, and were clearly different each from the other. No clear relationship has been established between the restrictase enzyme profiles and the tropism of the isolated viruses. Sequencing of isolated ВHV 4 strains showed homo­logy with the reference European strain Movar 33/63. After construction of the phylogenetic tree, three ВHV 4 strains were at one branch of the phylogenetic tree, while two other strains were at the branch of reference Movar 33/63 strain. Applied molecular biology methods can be successfully used for differentiation and detailed genetic characterisation of the isolated BHV 4 strains.

Sequencing and analysis of complete genome of the attenuated Hanvet1.VN strain used for vaccine production against porcine reproductive and respiratory syndrome

The porcine reproductive and respiratory syndrome virus (PRRSV) attenuated strain Hanvet1.VN has been developed by the Pharmaceutical and Veterinary Material J.S.C (HANVET) by passaging HY-2010 strain on MARC-145 cells for 80 passages and used for PRRS vaccine production. In this study, we sequenced and analyzed the whole genome of the attenuated Hanvet1.VN strain. The total RNA was extracted from the Hanvet1.VN strain, RT-PCR was used for amplification of 15 separate segments of the whole genome. The amplified segments were cloned into the pCR2.1 vector and sequenced by Sanger sequencing. The sequences were analyzed with BioEdit and DNA Star Software. The results showed that, GP5 of the Hanvet1.VN attenuated strain had 100% identity in amino acid (aa) sequences with one of the pathogenic Vietnamese strain isolated in Quang Nam Province and had 98% identity with that of the Chinese 07NM strain. However, the identity of aa sequence of the Hanvet1.VN GP5 was much lower in the comparison with GP5 of VR2332, and it was only 87%. The MP and NP proteins were highly conserved compared with pathogenic strains circulating in Vietnam (07QN) and China (07NM) (99-100%, respectively). The other eight proteins of the Hanvet1.VN strain showed changes from 1.2% in NP1a to 3.9% in GP2 compared with the 07QN strain. However, the aa identity of all Hanvet1.VN proteins were very low when compared with proteins of PRRSV type II strain (North American strain, VR2332), ranged from 86.25% to 97.7%. Our results showed that the Hanvet1.VN attenuated vaccine strain had protective immunogenicity similar to that strain circulating in Vietnam closely related to a strain from China but different from the type II North American strain VR2332. Hence, for importing PRRSV vaccine, especially from American or Europe Countries, antigenic compatibility of the PRRSV vaccine and strains circulating in Vietnam should be concerned in PRRSV vaccine production.

Genome Sequence of the Plant Growth Promoting Fungus Serendipita vermifera subsp. bescii: The First Native Strain from North America

Serendipita vermifera (=Sebacina vermifera) has demonstrated plant growth promoting abilities with little or no host specificity. The full genome sequencing of Serendipita vermifera subsp. bescii, the first North American strain, will provide insight into the mechanisms behind mycorrhizal symbiosis and plant enhancement in a variety of agronomically important crops.

Comparison of Immune Responses in Pigs Infected with Chinese Highly Pathogenic PRRS Virus Strain HV and North American Strain NADC-20

Introduction:Chinese HP-PRRSV characterized by high morbidity and mortality of all ages of pigs emerged since 2006 in China. The immune response of HP-PRRSV was never compared with conventional low pathogenic PRRSV strain.Objective:In this study, we compared the immune responses elicited by a Chinese HP-PRRSV strain HV and a North American RRSV strain NADC20 infections.Result:Pigs infected with NADC-20 showed significantly higher Ab titers than HV-PRRSV infected pigs at 9 DPI. Infection with HV-PRRSV induced a significantly higher levels of TNF-α and IL-10 in both sera and lung tissues and higher IFN-α and IFN-γ in the serum. Flow cytometry analysis showed that HV-PRRSV infected pigs generated significantly higher frequencies of NK cells in the peripheral blood and Th/memory, CTLs, and T-reg cells in the lung as compared with NADC-20 infected pigs.Conclusion:This study demonstrates that different immunity profiles were elicited by HV-PRRSV and NADC-20, and these differences may contribute to the distinct pathogenesis of HV-PRRSV and NADC-20.