Isolation of Trypanosoma caninum in domestic dogs in Rio de Janeiro, Brazil

• Published in: Parasitology 2010-09, Vol.137 (11), p.1653-1660
• Main Authors: DE S. PINTO, A. G., SCHUBACH, T. M. P., FIGUEIREDO, F. B., BAPTISTA, C., FAGUNDES, A., DA S. BARROS, J. H., DE PAULA, C. C., TOMA, H. K., MADEIRA, M. F.
• Format: Article
• Language: English
• Subjects: Animals; Animals, Domestic - parasitology; Antibodies, Protozoan - blood; Biological and medical sciences; Brazil; Brazil - epidemiology; dog; Dog Diseases - diagnosis; Dog Diseases - epidemiology; Dog Diseases - parasitology; Dogs; Domestic animals; Electrophoresis - methods; Fundamental and applied biological sciences. Psychology; General aspects; General aspects and techniques. Study of several systematic groups. Models; Invertebrates; isoenzymes; Isoenzymes - analysis; leishmaniasis; Molecular Sequence Data; Phylogeny; polymerase chain reaction (PCR); Polymerase Chain Reaction - methods; RNA, Ribosomal, 18S - genetics; Sequence Analysis, DNA; Skin - parasitology; Trypanosoma; Trypanosoma - classification; Trypanosoma - enzymology; Trypanosoma - genetics; Trypanosoma - isolation & purification; Trypanosoma caninum; Trypanosoma cruzi; Trypanosomatidae; Trypanosomiasis - diagnosis; Trypanosomiasis - epidemiology; Trypanosomiasis - parasitology; Trypanosomiasis - veterinary; Vector-borne diseases
• ISSN: 0031-1820; 1469-8161
• DOI: 10.1017/S0031182010000417

The domestic dog's involvement with different members of the Trypanosomatidae family has been the focus of several studies due to this animal's close proximity to man. Recently this animal has been infected by a new Trypanosoma species (T. caninum), described in Rio de Janeiro and 19 similar isolates were later obtained. The objective of this study was to identify these isolates. All samples were isolated from intact skin cultures and analysed morphologically, by biochemical isoenzyme electrophoresis assays and by several molecular PCR assays. Additionally, anti-Leishmania sp. antibodies were assessed using the indirect Immunofluorescence Antibody Test (IFAT) in all animals. The methodologies employed to identify the isolates, including partial nucleotide sequences of 18S rRNA gene, indicated patterns identical to T. caninum and patterns different from the other species, including T. cruzi and T. rangeli samples. A phylogenetic tree constructed with the partial 18S ribosomal sequence shows that T. caninum is clustered with T. pestanai. Ten (52·6%) animals presented anti-Leishmania sp. antibodies with titres varying from 1:40 to 1:320. Thus, the hypothesis that this protozoan has disseminated among the dogs in Rio de Janeiro must be considered. The importance of a correct diagnosis in those animals and the possible consequences in the areas where visceral leishmaniasis is found are discussed here.