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Brazilian Journal of Microbiology
Print version ISSN 1517-8382
NARDI JUNIOR, Geraldo de et al. Interference of vaccinal antibodies on serological diagnosis of leptospirosis in vaccinated buffalo using two types of commercial vaccines. Braz. J. Microbiol. [online]. 2007, vol.38, n.2, pp. 363-368. ISSN 1517-8382. http://dx.doi.org/10.1590/S1517-83822007000200033.
The vaccinal antibodies interference represents one of the Microscopic Agglutination test - MAT limitation in the animal leptospirosis serum diagnosis. Prospective studies showing the dimensions of this effect are rare in buffaloes. This study aimed to determine the anti-Leptospira serum agglutinin profile in vaccinated female buffaloes using two types of commercial vaccines against leptospirosis: bacterin (whole bacterial cell) and purified outer membrane and to evaluate the vaccinal interference on serum diagnosis. Three groups of 11 adult buffalo females were established: G1-control, non-vaccinated, G2- vaccinated with bacterin vaccine with six serovars, G3- outer membrane purified vaccine with five serovars. A booster dose was administrated 30 days after the first vaccination (dpv) and two re-vaccinations six months a part (210 and 390 dpv). Serum samples were collected on days 0, 15, 40, 45, 60 and every 30 days until 540 dpv. G1, G2 and G3 serum samples were submitted to MAT with the serovars present in the vaccines. G1 remained always negative. Both vaccines induced serologic responses in MAT at 150 dpv against all serovars and they revealed maximum titers around 45 and 60dpv as follows: Pomona: G2 (1600) and G3 (3200); Hardjo: G2 and G3 (1600); Wolffi: G2 (800) and G3 (1600); Icterohaemorrhagiae: G2 and G3 (800); Grippotyphosa: G2 and G3 (200) and Canicola: G2 (NR) and G3 (400). Even though, the Wolffi serovar is not present in the purified outer membrane vaccine, G3 showed a response to that serovar, probably due to cross reaction to the serovar Hardjo. The G3 titers were higher and appeared earlier than in G2, but with similar serologic profiles. At the re-vaccination there was an increase on agglutinin levels, but of less intensity than those previously observed. After six months from the second revaccination (540 dfv), G2 and G3 were almost negative, which demonstrated the short diagnostic interference.
Keywords : buffalo leptospirosis; vaccination; serum diagnosis; MAT.