Bio-Burden and bio-type profiles of mycobacterium avium subspecies paratuberculosis infection in suspected population of domestic livestock in India

Multiple diagnostic tests standardized in the laboratory are central to diagnosis of Mycobacterium avium subsp. paratuberculosis (MAP), cause of Johne’s disease (JD) in domestic livestock, Information on bio-burden of MAP infection at animal, species, region, state and National levels is limited in India. In absence of National prevalence estimates (bio-burden), the disease has not received due attention and priority for the control. Present study estimated bio-burden of MAP in domestic livestock from different agro-climatic regions of country. Clinical samples (faeces, blood and serum) of suspected animals from farm and farmer’s herds / flocks, submitted to CIRG, Makhdoom between 2010 and 2011, were screened using multiple diagnostic tests (microscopy and IS900 PCR on faecal blood and Indigenous ELISA on serum samples). Of the 716 faecal samples screened by microscopy, 50.9% were positive for acid-fast bacilli like MAP. of the faecal (n=183) and blood (n=510) samples screened using IS900 PCR; 27.3 and 19.6% were detected positive, respectively. Screening of 1598 serum samples (goats, sheep and cattle), by ‘Indigenous ELISA kit’ 68.4% were positive. The study reports very high bio-burden of MAP in domestic livestock population. Molecular characterization of MAP using IS1311 PCR-REA identified ‘Bison type’ as predominant biotype (98.6%) in domestic livestock population.