A complementary diagnosis of naturally occurring tuberculosis in water buffaloes (Bubalus bubalis) in Rio de Janeiro using a MPB70-ELISA, Brazil.

As tuberculosis is still a worldwide infection and buffalo breeding represents an important economic activity in various countries, the purpose of this study was to employ an enzyme-linked immunosorbent assay (ELISA) using MPB70 as a capture antigen for the diagnosis of naturally occurring tuberculosis in water buffaloes in Brazil. After the introduction of newly acquired cattle onto a tuberculosis (TB) free farm, an outbreak of TB was recorded in a mixed herd comprising water buffaloes (21) and cattle (46). The entire herd was tested by intradermal tuberculin injection (ITT) and positive animals were slaughtered and tested by culture, polymerase chain reaction (PCR), and ELISA. From the 21 buffaloes sampled, three were reactive by ITT. All the three had positive culture and ELISA, while PCR was positive in two of them. Besides that, one ITT-negative buffalo was slaughtered and presented positive results by both culture and ELISA, and was considered as anergic. Although there were only few animals, those findings demonstrate the diagnostic usefulness of an MPB70-ELISA to correctly detect Mycobacterium bovis tuberculosis in water buffaloes.