Information on Ovine Johne's Disease (OJD) is limited in the farmer's flocks in India. Target tissues of 39 sheep belonging to farmer's flocks were screened by tissue culture, direct tissue PCR and ELISA kit to estimate the presence of Mycobacterium avium subspecies paratuberculosis(MAP). Indigenous ELISA kit, originally developed for the screening of goats, was adapted for screening of sheep and was evaluated with respect to tissue culture and PCR. Soluble protoplasmic (PPA) antigen from MAP 'Bison type' strain cultured from a terminal case of JD in goat was used in ELISA. Decontaminated tissues pellets from intestines and mesenteric lymph nodes (MLN) were processed for DNA isolation and IS900 PCR. Positive DNA samples on amplification yielded specific 229 bp band. Of the 78 target tissues from farmer's flocks, live cultivable MAP was recovered from 64.1% sheep (41.0 in intestine and 38.9% MLN), respectively. Screening of tissues by specific IS900 PCR, 48.7% sheep were positive (33.3% each in intestine and MLN). Culture and PCR together detected 69.2% sheep positive for MAP (64.1%. in culture and 48.7% in PCR). Screening by ELISA kit, 46.1% were positive and together with culture kit detected 69.2% sheep positive (46.1% in ELISA and 64.1% in culture). On applying kappa statistics to direct tissues PCR and indigenous ELISA kit with 'Gold standard' tissue culture method, showed 'substantial agreement' both for direct PCR and ELISA kit. ELISA kit also showed 'substantial agreement' with tissues culture.

Using, 3 tests (culture, PCR and ELISA), 74.3% sheep were detected positive. In combinations of 2 tests, 69.2, 69.2 and 66.6% sheep were positive in culture and ELISA, culture and PCR and ELISA and PCR, respectively. Independently, 64.1, 48.7 and 46.1 sheep were positive in culture, PCR and ELISA, respectively. Screening of 39 serum samples by indigenous ELISA kit, 46.1, 30.7, 12.8, 7.6 and 2.5% sheep were in strong positive, positive, low positive, suspected and negative categories with respect to Johne's disease status (S/P ratio). The 46.1% sheep in strong positive category were considered positive for JD. Of these 18 (46.1%) positive sheep, 88.8 and 61.1% were positive in culture and PCR, respectively. The sensitivity and specificity of ELISA kit (goat based) in sheep was 66.6% and 83.3%, respectively.. Unlike 'sheep' genotype the sheep population in India were infected with MAP 'Bison type' genotype, which could be easily recovered from sheep tissues.