ABSTRACT
In Mexico, Triatoma longipennis (Usinger), Triatoma picturata (Usinger), and Triatoma pallidipennis (Stal), primary Chagas disease vector species of the phyllosoma complex, were analyzed by randomly amplified polymorphic DNA (RAPD). Sixteen decametric primers resolved individual profiles not identical, but partially discriminative between species. Analysis based on pairwise presence/absence comparisons between the three species was performed using three primers and two outgroup species Triatoma infestans (Klug) and Triatoma barberi (Usinger). Fifty-three bands in total were scored, although only two bands were constant among the three phyllosoma complex species. Two other bands were constant only for T. longipennis and T. picturata together, and not present in T. pallidipennis. Neighbor Joining tree and the multiple correspondence analysis discriminated T. pallidipennis clearly from the other two species, although there was overlap between T. longipennis and T. picturata. The results indicate a close relationship between the studied species and support the hypothesis of their recent evolution. The suitability of RAPD to discern populations within the species is discussed.
Subject(s)
Animals , Female , Male , Insect Vectors , Phylogeny , Random Amplified Polymorphic DNA Technique , Triatominae , Genetic Markers , Insect Vectors , TriatominaeABSTRACT
Genetic varibility 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, (i) temporal stability of genotypes found in Santa Rita de Siguas, (ii) high genetic differences between Arequipa and Santa Rita de Siguas populations suggesting minor contact between them, (iii) multiple origin of the T. infestans population in Arequipa, and (iv) poor dispersal capacity of T. infestans: the panmictic unit could be reduce 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, (i) a high genetic polymorphism, (ii) nine different multilocus genotypes were detected and clustered in two different clades, (iii) most of the parasite isolates pertained to one of the clade and were genetically similar to those analyzed 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.
Subject(s)
Animals , Triatoma/genetics , Trypanosoma cruzi/genetics , Isoenzymes/analysis , PeruSubject(s)
Humans , Male , Female , Child , Chagas Disease/diagnosis , Blotting, Southern , Bolivia , Polymerase Chain ReactionABSTRACT
Dois anticorpos monoclonais anticomponente 5 de Trypanosoma cruzi (I-35/115 e II-190/30) foram testados respectivamente em IFA e ELISA sobre 35 clones de T.cruzi isolados no laboratório. Entre estes 35 clones testados, 18 perfís isoenzimícos diferentes puderam ser detectados. Todos os clones foram reconhecidos exceto um clone que näo reagiu com o anticorpo monoclonal II-190/30. Estes resultados säo a favor da expressäo constante do componente 5 no meio do taxón T. cruzi
Subject(s)
Animals , Antibodies, Monoclonal , Antigens, Protozoan/analysis , Isoenzymes/analysis , Trypanosoma cruzi/immunology , Enzyme-Linked Immunosorbent Assay , Epitopes , Fluorescent Antibody Technique , Trypanosoma cruzi/geneticsSubject(s)
Adult , Humans , Male , Female , Chagas Disease/diagnosis , Bolivia , Immunoenzyme TechniquesABSTRACT
Realizamos um estudo comparativo entre o xenodiagnostico e os testes sorologicos para doenca de Chagas. Cento e cincoenta pacientes de algumas areas endemicas foram estudados. Quatro deles pareceram revelar um estado particular com um xenodiagnostico positivo e uma sorologia negativa, esta realizada com quatro diferentes tecnicas classicas (teste de inmunofluorescencia, ELISA: Enzyme Linked Immunosorbent Assay, teste de fixacao do complemento e teste de immuno-eletroforese). O soro de um dos pacientes que apresentou depressao humoral especifica mostra elevada quantidade de antigenos circulantes comprovada pela tecnica da immuno-eletroforese.Os autores sugerem o uso de um teste sorologico para detectar a presenca de antigenos circulantes de T. cruzi, alem da utilizacao de testes sorologicos classicos. Isto permitiria o diagnostico da doenca de Chagas em pacientes com uma baixa (ou mesmo inexistente) producao de anticorpos especificos