MODULAÇÃO DA RESPOSTA IMUNOLÓGICA DE CÃES UTILIZANDO BCG EM ASSOCIAÇÃO COM FRAÇÃO FLAGELAR DE LEISHMANIA AMAZONENSIS

Abstract

The aim of this study was to evaluate the protective effect of the flagellar fraction of Leishmania (L) amazonensis and BCG in dogs from endemic area for canine visceral leishmaniasis (CVL). Initially a study was conducted on an epidemiological survey in order to determine the frequency of antibodies against Leishmania in dogs of both sexes, with aged above six months and their correlation with clinical variables such as : hypertrophy of popliteal lymph nodes, skin lesions , onychogryphosis, cachexia and ocular lesions. A total of 341 dogs were used in this study. The serum of these animals was submitted to ELISA/S7 ® test. The serological results shwoed that 173 (50.73%) were positive and 135 (39.59%) were negative for anti-Leishmania antibodies. Among Seropositive animals was observed that 79 (45.66%) presented lymph node hypertrophy, 25 (14.45%) skin lesions, 23 (13.29%) onychogryphosis, 22 (12.72%) cachexia and 11 (6.36%) with the presence of ocular lesions. To evaluate the protective effect of flagellar fraction and BCG were evaluated 90 seronegative animals divided in three groups of 30animals: Group I - animals immunized with flagellar fraction doses of BCG and Group II - animals immunized with BCG and Group III - control animals inoculated with PBS. After immunization the animals remained in the endemic area and they were followed up during 14 months. For immunohistochemical analysis just 06 dogs of each group were selected randomly. However, all dogs were negative for the presence of anti-Leishmania, the immunohistochemical analysis showed amastigotes of Leishmania in the skin of 2 animals, one belonging to the Group II (5 parasites / field) and another belonging to the Group III (18 parasites / field ). The animals of group I (immunized with BCG and flagellar fraction) did not present parasites in the skin. In conclusion this study reinforce the same results obtained in murine model that immunization with flagellar fraction of L. amazonensis in combination with BCG is able to protect dogs analyzed, and the immunohistochemistry was more efficient in the diagnosis of CVL in this study.