Multi-antigen print immunoassay for seroepidemiological surveillance of bovine tuberculosis on Indian cattle farms.

Bovine tuberculosis caused by Mycobacterium bovis is a zoonotic disease that is responsible for significant economic losses in many countries. The standard diagnostic method, the tuberculin test (TST) that is used in control programmes has serious shortcomings and, given the complex nature and the economic impact of the disease, a number of other diagnostic methods have been examined. The authors have attempted to characterise antibody response using the multi-antigen print immunoassay (MAPIA). A total of 511 serum samples were collected from farms in India on which bovine tuberculosis was prevalent and on farms with low incidence. These were tested using the MAPIA against a panel of five defined M. bovis recombinant antigens and two purified protein derivatives (bovine PPD and avian PPD) to study the seroprevalence of the disease on Indian cattle farms. Results indicated that the fusion protein of antigen CFP-10:MPB83 showed a positive response in 142 out of 298 serum samples from tuberculosis-prevalent farms, thereby indicating the serological dominance of the proteins post infection. The antigen selected could be used further in the development of a simple, rapid and accurate serological diagnostic test, paired with TST, for use in bovine tuberculosis control programmes.

Recombinant mid gut antigen (Bm95) as a vaccine against Indian Rhiphicephalus haemaphysaloides in Bos indicus cattle.

In the present study, we report for the first time the efficacy of recombinant Bm95 mid gut antigen isolated from an Argentinean strain of Rhipicephalus microplus strain A in controlling the tick infestations in India. The synthetic gene for Bm95 optimized for expression in yeast was obtained and used to generate yeast transformants expressing Bm95 which was purified to apparent homogeneity. Liquid chromatography-mass spectrometry analysis of the purified protein confirmed its identity as Bm95. Vaccine was prepared by blending various concentrations of purified Bm95 with aluminium hydroxide as an adjuvant. Immunogenicity studies of the vaccine in rabbits and cattle indicated that the vaccine was highly immunogenic. The efficacy studies of the vaccine was done in cattle. Naïve Bos indicus cattle were vaccinated with the recombinant vaccine and were challenged with the larval, nymphal and adult forms of Rhiphicephalus haemaphysaloides. The vaccine protected the animals from larval, nymph and adult tick challenges with an efficacy of 98.7%, 84.6% and 78.9% respectively. The results obtained from the above studies clearly demonstrated the advantage and possibilities of the use of Bm95 in controlling R. haemaphysaloides infestations in the field.

Development of a recombinant epsilon toxoid vaccine against enterotoxemia and its use as a combination vaccine with live attenuated sheep pox virus against enterotoxemia and sheep pox.

Sheep pox and enterotoxemia are important diseases of sheep, and these diseases cause severe economic losses to sheep farmers. The present study was undertaken to evaluate the potential of formaldehyde-inactivated recombinant epsilon toxin as a vaccine candidate. The potency of the recombinant epsilon toxoid with aluminum hydroxide as an adjuvant in sheep was determined. Vaccinated sheep were protected against enterotoxemia, with potency values of >5 IU being protective. Further, the use of this construct in a combination vaccine against sheep pox resulted in the sheep being protected against both sheep pox and enterotoxemia.