Histo-Pathological and Serological Investigation on the Occurrence of Subclinical Paratuberculosis in Slaughtered Buffaloes in Mhow, Madhya Pradesh, India

Paratuberculosis, caused by Mycobacterium avium subsp. paratuberculosis (MAP), is an incurable chronic disease affecting virtually all ruminants. Although buffaloes are usually considered to be more resistant than cattle, bubaline paratuberculosis displays similar gross and histological lesions. The association of MAP with human Crohn’s disease poses a high risk of infection for slaughterhouse and dairy farm workers. The objective of the present study was to identify subclinical paratuberculosis in buffaloes slaughtered at Mhow cantonment abattoir, Madhya Pradesh, India. A total of 150 paired samples comprising serum (N = 50), tissues of the intestine (N = 50), and mesenteric lymph nodes (N = 50) from each animal were collected randomly from 50 buffaloes over a period of 3 months to perform the diagnosis by competitive ELISA for anti-MAP IgG detection in serum samples. Tissue samples were subjected to histopathology to classify the lesions in hematoxylin–eosin-stained tissue sections and to detect acid-fast bacilli in sister tissue sections on Ziehl–Neelsen staining. Anti-MAP antibodies were detected in 22.0% (11/50) of the serum samples. Among tissue samples, grade I, II, III, and IV lesions were observed in 24, 22, 4, 0 ileum, and 20, 24, 5, and 1 mesenteric lymph node samples, respectively. Acid-fast bacilli were observed in 6 ileum and 11 mesenteric lymph node samples. Overall, histological findings were more defined and illustrative than ELISA and can be used for the identification of paratuberculosis among slaughtered animals, especially in laboratories with limited resources. The findings also suggest an urgent requirement for the adoption of paratuberculosis control measures in the area.