Competitive enzyme-linked immunosorbent assay based on monoclonal antibody and recombinant hemagglutinin for serosurveillance of rinderpest virus.

A competitive enzyme-linked immunosorbent assay (C-ELISA) which detects antibodies unique to rinderpest virus (RPV) has been developed. This test can differentiate antibodies against RPV and those against peste des petits ruminants virus. The recombinant RPV hemagglutinin (H)-protein C-ELISA (recH C-ELISA) is based on the ability of a well-characterized monoclonal antibody (MAb) produced with the soluble, secreted form of the H protein (Sec H protein) of RPV made in a baculovirus expression system to compete with the binding of RPV antibodies in the serum of vaccinated or infected, recovered animals to the Sec H protein. The B-cell epitope recognized by the MAb corresponds to amino acids 575 to 583 on the H protein, which is not present on the antigenically closely related peste des petits ruminants virus hemagglutinin-neuraminidase protein. Initially, a positive-negative threshold cutoff value for percent inhibition of 34 was established with 500 known RPV-negative serum samples. The recH C-ELISA was developed with the enzyme immunoassay software of a commercial RPV C-ELISA kit. Comparative analysis of the test results for 700 serum samples obtained with the commercial kit gave a sensitivity of 112.4% and a specificity of 72.4%. Variations in percent inhibition values were observed for the two assay systems. These variations may have been due to the undefined amount of antigen present in the commercial kit as well as the use of a different MAb. The recH C-ELISA detected more positive serum samples compared to the number detected by the commercial kit, with the results confirmed by a virus neutralization test. Thus, recH C-ELISA is a sensitive tool for RPV serosurveillance in disease eradication programs.

Phytochemical investivations of indigofera tinctoria linn leaves.

Studies of Indigofera tinctoria Linn has shows that it possesses low toxicity. Phytochemical evaluation of leaf extract of Indigofera tinctoria Linn has been carried out to characterize some constituents present therein. Qualitative analysis of the extracts showed the presence of flavonoids, alkaloids, glycosides, terpenoids. Five compounds have been isolated from petroleum ether extract and methanolic extract and have been characterized by U.V.IR and H1 NMR data, petroleum ether extract were also characterized by HPTLC.

Prevalence of bovine viral diarrhoea virus antibodies in India.

A study was undertaken regarding the prevalence of bovine viral diarrhoea virus (BVDV) antibodies in bovine sera which tested negative for rinderpest and peste des petits ruminants virus antibodies. The samples were collected between January 1996 and December 1997. A total of 439 samples (327 cattle and 112 buffalo from 17 states of India) were tested using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The mean prevalence of BVDV antibodies in cattle was 15.29% (50/327) in 16 states compared to 23.21% (26/112) in buffalo in 9 states, with an overall prevalence of 17.31% (76/439) in 17 states. The serological evidence that BVDV infection is widespread in India is of utmost practical importance because of the clinical resemblance to rinderpest. A differential diagnosis between these two diseases is critical in view of the declaration by India of provisional freedom from rinderpest disease; active sero-surveillance is to begin in 2000 to achieve certification of freedom from rinderpest infection by the Office International des Epizooties.