Survival of avirulent thermostable Newcastle disease virus (strain I-2)in raw, baked, oiled, and cooked white rice at ambient temperatures

Raw white rice has not been considered a good carrierfor oral vaccination, probably because of its antiviralactivity. Methods are required to overcome antiviralactivity in raw white rice. This study was carried out todetermine the effects of various treatments of raw whiterice on the survival of strain I-2 of Newcastle diseasevirus. These included cooking and baking the rice ormixing the rice with vegetable oil prior to coating withvaccine virus. The vaccine-coated rice was then stored for30min and 24h, followed by quantitative recovery of thevirus. Thirty min after mixing, uncooked, cooked, andbaked rice, and rice mixed with vegetable oil showed titersof 10(6.2), 10(7.2), 10(6.6), and 10(7.0) EID50/0.1ml, respectively.After storage for 24h at 22-25oC, the titers dropped to10(5.0), 10(6.5), 10(5.0), and 10(6.0) EID50/0.1ml for uncooked,cooked, baked, and oiled rice, respectively.

Structural proteins of fowlpox virus vaccine strain and field isolates.

Structural polypeptides of IVRI vaccine strain and two field isoaltes of Fowlpox virus (Bareilly isolate and Panchmahal isolate) were analysed on SDS-PAGE and by immunoblotting technique. In 5%-20% gradient acrylamide gel 31, 29 and 31 polypeptide bands and in 7.5%-15% gradient gel 45, 37 and 39 polypeptide bands were detected after Coomassie blue staining respectively for Bareilly isolate, Panchmahal isolate and IVRI vaccine strain. The molecular weight (MW) of the polypeptides ranged from 226.10 to 10.30 kDa with total MW of 2650.12, 2259.50, and 2378.68 kDa respectively for the three viruses. The immunoblot revealed 35, 29 and 30 immunogenic polypeptides indicating most virion polypeptides to be immunogenic in nature. Although most polypeptides had similar electrophoretic pattern both in SDS-PAGE and immunoblotting, still the three viruses could be differentiated. The viruses were found to be antigenically different with Panchmahal isolate lacking the polypeptides 81.15, 76.33, 39.30, 37.50 and 29.35 kDa and the vaccine strain lacking 76.33, 37.50 and 29.35 kDa polypeptides as were present in Bareilly isolate.