Coinfection of gastrointestinal parasites with paratuberculosis in naturally infected sheep.

Abstract

Background and aim: Mycobacterium avium subspecies paratuberculosis (MAP) causes Johne's disease (paratuberculosis), which is a chronic wasting disease. No previous study has been found to investigate the coinfection of gastrointestinal parasites with paratuberculosis. This study aimed to investigate the relationship between paratuberculosis and gastrointestinal parasitism in naturally infected local Awassi (AS) and imported Tsurcana (TS) sheep.

Materials and methods: A total of 207 sheep (118 AS and 89 TS) were randomly selected from local butcher shops and slaughterhouses. Fecal and tissue samples from the ileum and mesenteric lymph nodes were collected. Fecal samples were screened for the presence of parasitic ova and oocysts. Hematoxylin-and-eosin-stained and Ziehl-Neelsen-stained tissues were examined for evidence of inflammation, acid-fast bacteria, and parasitic structures. Risk factor analysis was performed using multivariate logistic regression analysis.

Results: Mucosal thickening and corrugation of the ileum were found in AS sheep (74/113 [65.5%], 10/113 [8.8%], respectively) and TS sheep (21/88 [23.9%], 8/88 [9.1%], respectively). Histopathologically, diffuse multibacillary/histiocytic form was detected only in the AS sheep breed. AS sheep had higher levels of acid-fast bacteria in the ileum (70/113 [61.9%]) compared with TS sheep (34/88 [38.6%]). In addition, parasitic structure and severe eosinophilic inflammation were detected in AS (10/113 [8.8%], 108/113 [95.6%], respectively) and TS sheep (2/88 [2.3%], 70/88 [79.5%], respectively). Parasitic infections were detected in fecal samples from 15/118 (12.7%) AS sheep and 11/89 (12.4%) TS sheep. Coinfection between gastrointestinal parasites and paratuberculosis was detected histologically in 8/118 (7.1%) and 2/88 (2.3%) AS and TS sheep, respectively.

Conclusion: Risk factor analysis indicated that the ileum from the AS sheep breed was 2.164 times more likely to have acid-fast bacteria and 2.874 times more likely to have eosinophilic infiltrations than the TS sheep breed. Results of this preliminary study may indicate the role of the sheep in the pathogenesis and shedding of MAP.