One-tube and one-buffer system of RT-PCR amplification of 1D gene of foot-and-mouth disease virus field isolates.

A method of reverse transcription (RT) and polymerase chain reaction (PCR) amplification of 1D (VP1) gene of foot-and-mouth disease (FMD) virus using one reaction mixture containing both avian myeloblastosis virus (AMV) reverse transcriptase (RTase) and Tfl DNA polymerase is described. The procedure was time saving, made use of a single buffer for both RT and subsequent amplification and performed better than the two-step procedure usually conducted with Moloney murine leukemia virus (MMLV) RTase and Taq DNA polymerase for amplification of the VP1 gene of field isolates of FMD virus serotypes O,-A, C and Asia 1. The failure to amplify the VP1 gene of many type O and Asia 1 viruses using MMLV RTase-Taq polymerase enzyme system could be overcome by performing RT of the viral genome at a higher temperature (48 degrees C) with AMV RTase which is not possible with MMLV RTase.

Escape mutants of foot-and-mouth disease virus selected by monoclonal antibodies directed to a trypsin-sensitive neutralization epitope.

Five monoclonal antibodies (MoAbs) against Indian reference/vaccine strain of foot-and-mouth disease (FMD) virus subtype A22 (IND17/77) and a guinea pig antibody against a synthetic peptide representing amino acids (aa) 136-151 of VP1 polypeptide of A22 virus were used in the study. All the antibodies either failed to react or showed a reduced reactivity with trypsin-treated (TT)-146 S virus particles in enzyme-linked immunosorbent assay (ELISA), and could neutralize the infectivity of the reference virus. The antibodies were hence identified as specific to a trypsin-sensitive neutralizable antigenic site of the virus.

Selective excitation of tryptophans in OmpF: a fluorescence emission study.

The fluorescence studies of E. coli porin OmpF at pH 7.5 were carried out using excitation at 280 and 305 nm.

Antinuclear antibody in chickens with reoviral arthritis.

Antinuclear antibody (ANA) in chickens infected with reovirus was first detected at 3 weeks postinfection (PI). The antibody titer was greatest at 10 weeks PI (1:2560) and then declined. From 19 to 30 weeks PI, the birds were negative for ANA.

Experimental studies on Marek's disease in Japanese quail (Coturnix coturnix japonica).

Day-old quails experimentally infected with Marek's disease (MD) virus of quail origin developed lymphoid tumors. The severity of the disease increased considerably with serial passage. Tumor transplants could be made with cells derived from gross tumors in skeletal muscles, spleen cells, and blood from MD-affected quails.