Experimental Infection of Foot and Mouth Disease in Indian Sheep and Goats.

Foot-and-mouth disease (FMD) is an economically important contagious disease of livestock mainly cattle, buffalo, sheep, goats, and pig. There is limited data available on pathogenesis of foot and mouth disease in goats. In the study, the sheep and goats were infected experimentally with a serotype O foot-and-mouth disease virus by different challenge routes. The sheep and goats challenged by coronary band route and coronary band and intra-dermo-lingual route exhibited FMD clinical signs at 2-5 days post challenge. Whereas intra-dermo-lingual challenged sheep and goats did not exhibit FMD clinical signs. Live virus could be isolated from blood of infected sheep and goats at 2-5 days post challenge. Viral RNA could be detected from blood of infected sheep and goats at 1-10 days post challenge. The neutralizing antibody titre was detected at 10 days post challenge and maintained up to 35 days post challenge in all infected sheep and goats. Non structural protein (NSP) antibodies were detected as early as 5-10 days post challenge and remain positive up to 35 days post challenge in the infected sheep and goats. In conclusion, the pathogenesis of sheep and goats with serotype O foot and mouth disease virus by different challenge routes could be demonstrated.

Recombinant haemagglutinin protein of highly pathogenic avian influenza A (H5N1) virus expressed in Pichia pastoris elicits a neutralizing antibody response in mice.

Recombinant avian influenza vaccines offer several advantages over the conventional vaccines. In this study, the haemagglutinin (HA) gene of highly pathogenic avian influenza H5N1 was cloned and expressed as His tagged protein in methylotropic yeast Pichia pastoris. The expression of recombinant HA (rHA) protein was confirmed by SDS-PAGE and western blot analysis. The rHA protein was purified using Ni-NTA affinity chromatography under denaturing conditions and the functions of the protein was assessed by the haemagglutinin assay after refolding. The immunogenicity of the rHA was evaluated by immunizing four groups of mice with different payloads (2.5, 5.0, 10 and 25µg) of purified rHA and the production of rHA specific antibodies were analysed by haemagglutinin inhibition assay (HI) and enzyme-linked immunosorbent assay (ELISA). An antigen specific immune response was observed against rHA indicating that the rHA antigen could be used as a vaccine candidate against avian influenza. These results suggest that this strategy would pave the way for the development of rapid and cost effective method for the production of an avian influenza vaccine.