First Pathological, Molecular and Serological Investigation of Ovine Johne's Disease (Paratuberculosis) in Northeastern Algeria

Abstract

Paratuberculosis (PTCB) or Johne's disease (JD) caused by a slow growing acid fast bacillus Mycobacterium avium subspecies paratuberculosis (MAP), is an infectious disease of many species including humans. The disease is responsible for important economic losses to livestock industry worldwide. Although the disease is widespread, it had not been studied in Algerian sheep. In this study we inspected the presence of the infection in sheep (aged 2 years old or older) using histopathology and IS900-PCR techniques in randomly 378 tissues (ileum, ileoceacale valve and lymph nodes) and fecal samples. Gross lesions were detected in 16 (4%) of samples. Histopathological examination revealed the presence of pathognomonic lesions of JD in 61 (14%) animals. Ziehl-Neelsen (ZN) staining of tissue samples was positive in 28 (7%) cases. MAP-DNA was detected in 34 (9%) fecal samples. 14 (4%) animals were tested positive for antibodies against MAP. This study showed that not only ovine paratuberculosis present in Algeria but infected animals are excreting the bacteria in feces. This could be a significant threat for other ruminants and humans. Other studies should be carried out in order to better understand the prevalence and the molecular epidemiology of MAP in the country.