نادر مصوری
روح الله کشاورز
رسول مدنی
علی میرجلیلی

Paratuberculosis was first described in 1830's. Isolation and identification of the causative agent, Mycobacterium avium subsp. paratuberculosis (MAP) however did not materialize until 1910. This pathogen similar to majority of other mycobacteria, is fastidious in laboratory culture. There are satisfactory laboratory and pathological observations to consider MAP as an etiological element in Crohn's disease in human. In the Iranian environment, the disease is currently dispersed across the country affecting a large number of cattle, sheep and goat herds. The extent of MAP-imposed economical losses in ruminant farming sector of Iran remains unknown but seems to be huge. Bacterial culture, paratuberculination, agar gel diffusion test, complement fixation test, ELISA and Gama Interferon are some of the most conventional tests available for diagnosis of MAP infections in animals. Elisa is an OIE-approved test suitable for disease screening at herd level. In order to provide a self-reliance domestically developed ELISA system required for a national-scale disease control scheme, we have conducted the present study. Based on a three-phase research, the required 34 KD target antigen was first achieved through mass culture of MAP III &V laboratory strain. The second phase focused on designing the ELISA system itself with its efficiency assessed through comparative analysis against a reference ELISA kit approved by OIE. Analyzing results from all the three phases, revealed while our domestically developed ELISA system is promising in terms of disease diagnosis but it suffers from deficiency in accuracy requiring technical adjustments. We believe these initial findings deserve further work if such diagnostic system is expected to receive credit from the international scientific community.