H. de Mores Pereira from the State University of Maranhão, São Luís, MA, Brazil and seven colleagues describe the high prevalence of subclinical paratuberculosis in Buffaloes (Bubalus bubalis) in a northeast region of Brazil. Their publication appears in the Brazilian Journal of Microbiology (published 14 April 2020). According to Wikipedia, Buffaloes are extensively used there for meat and dairy production. In 2005, the water buffalo herd in the Brazilian Amazon stood at roughly 1.6 million head, of which 460,000 were located in the lower Amazon floodplains.
Photo credit: By Kleomarlo – Own work, CC BY-SA 3.0
Paratuberculosis is an infectious, chronic, and incurable disease that affects ruminants, causing enteritis and chronic granulomatous lymphadenitis, characterized by malabsorption syndrome, its agent is the Mycobacterium avium subsp. paratuberculosis (MAP). Thus, the objective of this work was to identify and characterize MAP in buffalo herds slaughtered in Baixada Maranhense region. Samples of intestines, mesenteric lymph nodes, and ileocecal valves were collected from 115 buffaloes slaughtered at Baixada Maranhense slaughterhouses to perform the diagnosis by histopathological examination using staining with Hematoxylin and Eosin (H&E) and Ziehl-Neelsen, bacterial isolation, and real-time PCR. In the histopathology by H&E staining, there was evidence suggestive of paratuberculosis in 30% (31/115) of the buffaloes. With Ziehl-Neelsen staining, acid-fast bacilli (AFB) were visualized in 27% (26/115) of the tissue samples analyzed. MAP was isolated in 4.3% (5/115) of the fecal samples subjected to bacterial culture. The samples inoculated in HEYM with mycobactin J produced colonies identified with MAP according to their own morphological characteristics such as round, white, smooth and slightly rough, alcohol-acid staining, and slow growth with 8 weeks of incubation and mycobactin dependence. The agent confirmation was performed in five bacterial isolates (4.3%) and 15 (13%) fragments of jejunum, ileum, and mesenteric lymph node by the IS900 real-time PCR technique. The results of the present study demonstrate the subclinical occurrence of paratuberculosis in flocks of buffalo slaughtered in slaughterhouses of Baixada Maranhense.