Uso da imuno-histoquímica no diagnóstico de leptospirose em primatas neotropicais / Role of immunohistochemistry in the diagnosis of leptospirosis in neotropical primates

ABSTRACT

Background: Leptospirosis is considered the most widespread zoonosis worldwide, occurring more frequently in tropical and developing regions. The aim of the present study was to detect the presence of Leptospira spp. in different primate tissues, using immunohistochemical (IHC) assays, taking advantage of the considerable number of necropsies compatible with a diagnosis of leptospirosis in neotropical primates at the Animal Pathology Laboratory (APL) of the University of Passo Fundo (UPF) in the northern region of Rio Grande do Sul. Materials, Methods & Results: Paraffin-embedded primate tissue samples were selected from necropsy examinations and subjected to IHC. The streptavidin-biotin-peroxidase method was used with diaminobenzidine chromogen (DAB) to verify immunostaining. Of the101 primates tested for Leptospira spp., 51.48% were positive; taining was distributed between lung (76.92%), liver (44.23%), and kidney (32.69%) tissue. Analysis of the combined anatomopathological verification data of the studied organs revealed a high frequency of lesions commonly observed in the tissues of animals exposed to the pathogen. For complementary diagnosis, an anti-Leptospira spp. antibody test was performed in primates at the UPF-Zoo, from which a population of the necropsied animals originated. The microscopic agglutination test (MAT) was utilized, which demonstrated 90.47% positivity in 21 individuals; sejroe and panama were the most frequent serovars. Discussion: Different intensities of tissue immunostaining were observed. Areas of fragmented or diffuse staining were considered to indicate equal positivity to that indicated by areas of staining with preserved morphology. Of 52 Leptospirapositive primates, most presented some degree of staining in lung samples, which shows a high level of involvement for this organ in primate leptospirosis. […](AU)