Occurrence of caseous lymphadenitis in goats from a slaughterhouse in the Brazilian Northeast

Résumé

Caseous lymphadenitis (CLA) is a chronic zoonosis that affects small ruminants globally. CLA is sometimes characterized by its visceral form, which may be associated with late diagnosis during postmortem inspection only. Alternatively, serological diagnosis could be used in the subclinical CLA cases detection due to its high sensitivity. Here, the occurrence of CLA in goats slaughtered in Mossoró, Rio Grande do Norte (RN) state, Brazil, was determined and indirect Enzyme Linked Immunosorbent Assay (ELISA) and microbiological culture methods were compared. Serum samples were collected from 150 goats and used to perform indirect ELISA using a supernatant of Corynebacterium pseudotuberculosis as an antigen. Goats were inspected after slaughter and fragments from internal organs suspicious of CLA were collected for microbiological culture. Indirect ELISA detected anti-C. pseudotuberculosis antibodies in 11.33% (17/150) of goats, while C. pseudotuberculosis was detected by microbiological culture in only 2% (3/150). The kappa index (κ = 0. 275) presented a weak agreement between ELISA and microbiological culture. In conclusion, despite the considerable proportion of CLA in goats from a slaughterhouse in Mossoró-RN, there was low detection of C. pseudotuberculosis in microbiological culture, denoting the higher sensitivity of ELISA. These facts could be associated with the long incubation period of C. pseudotuberculosis and the early seroconversion of goats infected.