Detection of Chagas infections using Trypanosoma evansi crude antigen demonstrates high cross-reactions with Trypanosoma cruzi

Antigenic similarities between salivarian trypanosomes are known for a long time, but similarities between salivarian and stercorarian trypanosomes have been very little investigated. Phylogenetically, these genus and species appear to be far. However, in a preliminary work we had shown strong reactions of chagasic human sera using T evansi antigens in Western-blotting and ELISA. In the current work an ELISA test using T evansi crude antigens was probed with one hundred and two sera of chagasic Bolivian patients previously diagnosed which presented different pathologies. The sensitivity of the ELISA T evansi was 92.6% similar to that of ELISA T cruzi. The specificity evaluated using 20 sera of patients infected by Leishmania sp. reaches a comparable value of that obtained with the T cruzi immunofluorescent in in unotl uore scent assay. Finally, the sensitivity and the specificity of the ELISA T evansi were not really different from conventional serology of Chagas. In spite of their taxonomic position in various sections and their old divergence, these observations prove a strong antigenic community between T cruzi and T evansi. Consequently, the common antigens which remain to be characterized, could be an alternative source of antigen for the detection of antibodies against T cruzi. Given that T evansi seems to have strong antigenic communities with the majority of the pathogenic current trypanosomoses f mammals, it is very attractive to identify and characterize these highly conserved antigens which could be suitable targets to develop tools for diagnosis, prophylaxy and chemotherapy against several human and animal trypanosomoses

Genetic variability and microdistribution of Triatoma infestans genotypes and Trypanosoma cruzi clones in Arequipa region (Peru)

The genetic variability of #Triatoma infestans and #Trypanosoma cruzi populations was studied by isoenzyme analysis in two distinct areas of Arequipa province (Peru) ; one, Santa Rita de Siguas, being an endemic area for Chagas' disease, the second, Arequipa, recently infected. Analysis of #T. infestans genetic variability indicates, temporal stability of genotypes found in Santa Rita de Siguas, high genetic differences between them, multiple origin of the #T. infestans population in Arequipa, and poor dispersal capacity of #T. infestans : the panmictic unit could be reduced to a house. Parasite isoenzyme analysis was performed in 29 peruvian stocks of #T. cruzi, mainly isolated from bugs taken in a single locality, Santa Rita de Siguas. The results show, a high genetic polymorphism, nine different multilocus genotypes were detected and clustered in two different clades, most of the parasite isolates pertained to one of the clades and were genetically similar to those analysed 12 years before. This sample allowed the study of the mating system of #T. cruzi in strict sympatic conditions and gave more strength to the hypothesis of the clonal structure of #T. cruzi populations. (Résumé d'auteur

Genetic variability and microdistribution of Triatoma infestans genotypes and Trypanosoma cruzi clones in Arequipa region (Peru)

The genetic variability of #Triatoma infestans and #Trypanosoma cruzi populations was studied by isoenzyme analysis in two distinct areas of Arequipa province (Peru) ; one, Santa Rita de Siguas, being an endemic area for Chagas' disease, the second, Arequipa, recently infected. Analysis of #T. infestans genetic variability indicates, temporal stability of genotypes found in Santa Rita de Siguas, high genetic differences between them, multiple origin of the #T. infestans population in Arequipa, and poor dispersal capacity of #T. infestans : the panmictic unit could be reduced to a house. Parasite isoenzyme analysis was performed in 29 peruvian stocks of #T. cruzi, mainly isolated from bugs taken in a single locality, Santa Rita de Siguas. The results show, a high genetic polymorphism, nine different multilocus genotypes were detected and clustered in two different clades, most of the parasite isolates pertained to one of the clades and were genetically similar to those analysed 12 years before. This sample allowed the study of the mating system of #T. cruzi in strict sympatic conditions and gave more strength to the hypothesis of the clonal structure of #T. cruzi populations. (Résumé d'auteur