High prevalence of subclinical paratuberculosis in buffaloes (Bubalus bubalis) in Maranhão, Brazil.

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.

First molecular epidemiological study of Mycobacterium avium subsp. paratuberculosis in cattle and buffalo from different regions of Brazil.

Paratuberculosis is an incurable disease in ruminants with great worldwide economic impact, caused by Mycobacterium avium subsp. paratuberculosis (MAP). The objective of this study was to carry out a study of the molecular epidemiology of the MAP using the restriction enzyme analysis (REA) technique of IS1311 MAP region in biological samples of feces, intestinal tissue, and mesenteric lymph nodes of cattle and buffaloes from six Brazilian states. In total, 109 samples of feces and tissues of cattle and buffaloes were collected from animal paratuberculosis suspected. Twenty-five samples were positive in the detection of the DNA of the IS900 region of MAP and it was possible to type 18 strains in the analysis of the region IS1311, being 100% of them identified as belonging to subtype Bison MAP strain. This is the first epidemiological molecular study of MAP in Brazil. The results indicate that paratuberculosis is widespread in cattle and in buffaloes in several regions of Brazil, and the subtype Bison MAP strain was the only one identified in the samples analyzed in this study, demonstrating the similarity between the strains from different states tested. These results provide the necessary support for the implementation of paratuberculosis control strategies in cattle and buffaloes in Brazil.