Serologic and pathologic characterization of infection by Mycobacterium avium subsp paratuberculosis in red deer from Argentina

VERNA A, MORSELLA C, CASARO A, PAOLICCHI F.

Bilbao, Spain

Congreso; 7th International Colloquium on Paratuberculosis; 2002

  Deer farming is now widespread throughout Argentina, having paratuberculosis been identified in red deer (Cervus elaphus) herds in Buenos Aires state. This study examined 332 animals with different ages (8 to 84 months), selected at random and divided into seven groups, 50 % females and 50 % males each. Other seven seropositive animals were selected for having been shown paratuberculosis clinical signs. Blood for indirect ELlSAs (ELlSA 1, and ELlSA 2) and AGlD was collected. Feces and tissues of Mycobacterium avium subsp. paratuberculosis (Map) for isolation were cultured on Herrold's with and without mycobactin. ELlSA 2 test results showed (using deer anti-lgG) significant higher percentage of animals reactor than animals with AGlD. While there were no significant differences found in percentages when ELlSA 1 (using bovine anti- 19G) test was compared with AGlD test. On the other hand ELlSA 1 detected a higher percentage in 12 and 84 months age strata, whereas ELlSA 2 and AGlD test detected a high percentage in 17 and 84 months animals. The three tests analysis proved the highest seropositive incidence in animals occurred within the 84 month old males group. Both ELlSAs absorbance values were highly correlated (r = 0.865). ELlSA 1 test had 83.3 % sensitivity while the AGlD test turned out having 33 % sensitivity. Mesenteric lymph nodes of animals with paratuberculosis had moderated to severe infiltration with macrophages (MO) as well as Langhans' giant cells (LC). Lesions observed were similar to lIlb and lIlc types established in small ruminants. All ZN were positive to MO and LC lymph nodes while intestine sections were positive to immunohistochemistry, showing the highest specificity to Map inside MO and LC.