Prevalence and molecular epidemiology of Johne's disease in Egyptian cattle.

Johne's disease is chronic enteric incurable disease in ruminant, is caused by Mycobacterium avium subsp. paratuberculosis (MAP). The data about incidence and economic importance of the disease in Egypt are scare. The present study investigated the prevalence of Johne`s disease among cattle in some localities in Egypt. The results revealed that the infection was significantly higher in older animals than young animals (P = <0.05). The prevalence of the disease was higher in Gharbia governorate (19.6%) in comparison with other studied area. To determine the efficiency of diagnostic tests, 138 fecal samples were examined by culture and real-time PCR, the result showed slight agreement between both tests for detection of MAP in feces. Sequence analysis of IS1311 gene for isolated MAP strain from Egypt revealed high identity (98%) with other MAP strains from Germany and Netherland. MAP belongs to a subspecies genetically different from Mycobacterium avium subsp. Hominissuis (MAH) and Mycobacterium avium subsp. avium (MAA), therefore these results are as would be expected. This study confirms the circulation of MAP among cattle in Egypt and highlights the need for more study on the disease in the Middle East.