Kumar, O.R. VinodhFaris, D.Senthil, N.R.Gunaseelan, L.TANUVAS2016-07-042016-07-042012-06http://krishikosh.egranth.ac.in/handle/1/68419Sixty three paratuberculosis suspected dairy animals were taken for this study and subjected to single intradermal test, faecal culture and IS900 nested PCR. Thirty three animals were found positive by single intradermal test, 40 samples were positive by faecal culture and 58 samples were positive by nested PCR. 40 faecal samples out of 63 were positive by IS900 primary PCR assay for Mycobacterium avium subsp. Paratuberculosis (Map) and 23 faecal samples, which gave negative results in the primary PCR, were subjected to secondary PCR assay. Of the 23 samples, 18 samples gave positive results in the IS900 nested PCR (nPCR), giving better sensitivity than single amplification PCR. The chi-square analysis showed a highly significant difference between the tests (P<0.01). The percentage positivity of single intradermal test, faecal culture and nested PCR assay in this study was 52.38% (33/63), 63.49% (40/63) and 92.06% (58/63), respectively. This study suggests that IS900 nested PCR could be used as a potential diagnostic tool in animals suspected of paratuberculosis.enArticle