Vol. 8, Issue 4 (2019)

Author(s):
Gokul Chand, PP Goswami and NS Prasad

Abstract:
Johne’s disease or paratuberculosis is a chronic progressive granulomatous enteritis of ruminants caused by Mycobacterium avium subsp. Paratuberculosis (Map). It causes significant economic losses in livestock industries worldwide. In the United States, Map-positive herds experience economic losses of almost US $100 per cow and a disease cost of US $200 to 250 million annually. ELISA based assay is ideal and sensitive for the screening of sera from infected animals, but it requires equipment and skilled technicians. The development of rapid, simple and specific assay is crucial for detection and surveillance of Map infection in animals. Therefore in the present study, the recombinant proteins from E. coli harboring pQE862 C+ and pQE1637 N+ clones respectively encoding 17.8 kDa and 20.8 kDa proteins were purified with the aim of developing ELISA based test as well as lateral flow assay for detection of paratuberculosis in infected animals. The recombinant antigens purified by affinity chromatography were used for conjugation with gold nanoparticles, spotted as test line and purified recombinant antibody raised in guinea pigs used as control line on nitrocellulose membrane. Five positive and five negative commercial ELISA kit tested samples were used in this experiment. Both antigens found efficacious in ELISA and LFA for diagnosis of paratuberculosis. Though a large number of samples are required for proper validation yet Overall, the developed test will be useful to farmers in future to devise suitable control programme and also to prevent the spread of paratuberculosis infection in other animals.