Induction of phagocytic activity and nitric-oxide production in natural populations of Trypanosoma cruzi I and II from the state of Paraná, Brazil.

Twelve strains of Trypanosoma cruzi isolated from wild reservoirs, triatomines, and chronic chagasic patients in the state of Paraná, southern Brazil, and classified as T. cruzi I and II, were used to test the correlation between genetic and biological diversity. The Phagocytic Index (PI) and nitric-oxide (NO) production in vitro were used as biological parameters. The PI of the T. cruzi I and II strains did not differ significantly, nor did the PI of the T. cruzi strains isolated from humans, triatomines, or wild reservoirs. There was a statistical difference in the inhibition of NO production between T. cruzi I and II and between parasites isolated from humans and the strains isolated from triatomines and wild reservoirs, but there was no correlation between genetics and biology when the strains were analyzed independently of the lineages or hosts from which the strains were isolated. There were significant correlations for Randomly Amplified Polymorphic Deoxyribonucleic acid (RAPD) and biological parameters for T. cruzi I and II, and for humans or wild reservoirs when the lineages or hosts were considered individually.

Induction of phagocytic activity and nitric-oxide production in natural populations of Trypanosoma Cruzi I and II from the state of Paraná, Brazil / Indução da atividade fagocitária e produção de óxido nítrico numa população natural de Trypanosoma cruzi I e II do Estado do Paraná, Brasil

Twelve strains of Trypanosoma cruzi isolated from wild reservoirs, triatomines, and chronic chagasic patients in the state of Paraná, southern Brazil, and classified as T. cruzi I and II, were used to test the correlation between genetic and biological diversity. The Phagocytic Index (PI) and nitric-oxide (NO) production in vitro were used as biological parameters. The PI of the T. cruzi I and II strains did not differ significantly, nor did the PI of the T. cruzi strains isolated from humans, triatomines, or wild reservoirs. There was a statistical difference in the inhibition of NO production between T. cruzi I and II and between parasites isolated from humans and the strains isolated from triatomines and wild reservoirs, but there was no correlation between genetics and biology when the strains were analyzed independently of the lineages or hosts from which the strains were isolated. There were significant correlations for Randomly Amplified Polymorphic Deoxyribonucleic acid (RAPD) and biological parameters for T. cruzi I and II, and for humans or wild reservoirs when the lineages or hosts were considered individually.

Doze cepas de Trypanosoma cruzi isoladas de reservatórios silvestres, triatomíneos e de pacientes chagásicos crônicos do Estado do Paraná, Brasil, classificadas como Tc I e II foram usadas para avaliar a correlação entre genética e diversidade biológica. Índice fagocítico (IF) e produção de óxido nítrico (ON) in vitro foram os parâmetros biológicos utilizados. O IF de cepas T. cruzi I e II não diferiram significativamente assim como o IF de cepas isoladas de humanos, triatomíneos ou de reservatórios silvestres. Há diferença estatística na inibição da produção de ON entre T. cruzi I e II e entre parasitos isolados de humanos e de cepas isoladas de triatomíneos e reservatórios silvestres, mas não foi observada correlação entre genética e biologia quando as cepas foram analisadas independentemente da linhagem ou hospedeiros das quais elas foram isoladas. Observou-se correlação significativa para amplificação aleatória do DNA polimórfico e parâmetros biológicos de Tc I ou II e para os seres humanos ou reservatório silvestre quando linhagens ou hospedeiros são consideradas separadamente.

Trypanosoma cruzi: Different methods of data analysis to evaluate the genetics-biology relationship.

The correlation of genetic and biological diversity in Trypanosoma cruzi was studied. Strains of T. cruzi II, isolated from humans; and of T. cruzi I, isolated from wild-animal reservoirs and from triatomines in the state of Paraná, Brazil, were used. Thirty-six biological parameters measured in vitro and six in vivo, related to growth kinetics and metacyclogenesis, susceptibility to benznidazole, macrophage infection, and experimental infection in mice were evaluated. Data from RAPD and SSR-PCR were used as genetic parameters. Mantel's test, group analysis, principal components analysis (PCA), and cladistical analyses were applied. With the Mantel's test, a low correlation was observed when parameters related to growth kinetics and metacyclogenesis in vitro and development of the experimental infection in vivo were included. The group analysis defined two groups that were separated as to whether they produced patent parasitemia in BALB/c mice. In the larger group, strains derived from wild reservoirs were separated from strains derived from triatomines and humans. The PCA identified two groups that differed as to whether they produced a parasitemia curve in mice. The cladistical analysis supported the previous results. This study shows the importance of the parasite-host relationship for the behavior of the strains, and that the combination of methods supports, extends, and clarifies the available information.

Genetic diversity of Trypanosoma cruzi natural populations in Paraná state, southern Brazil

As características genéticas de doze cepas de Trypanosoma cruzi, isoladas de pacientes chagásicos crônicos, triatomíneos e reservatórios silvestres do estado do Paraná, sul do Brasil, foram estudadas, utilizando as técnicas de RAPD (DNA polimórfico amplificado randomicamente) e SSR-PCR (Reação em Cadeia da Polimerase ancorada em seqüências repetidas pequenas). As cepas Sylvio e Esmeraldo foram utilizadas como referências para T. cruzi I e II, respectivamente. O DNA foi amplificado, utilizando três diferentes iniciadores para o RAPD e o iniciador (CA)8RY para o SSR-PCR. A análise do gel foi feita visual e computacionalmente, baseada na presença e na ausência de bandas. Os fenogramas mostraram a existência de dois grupos genéticos distintos: um contendo as cepas isoladas de pacientes chagásicos crônicos, que gruparam com Esmeraldo, e o outro contendo as cepas isoladas de triatomíneos e reservatórios silvestres, que gruparam com Sylvio. A existência de dois grupos filogenéticos do T. cruzi no Estado do Paraná é descrita pela primeira vez.

The genetic characteristics of twelve Trypanosoma cruzi strains isolated from chronic chagasic patients, triatomines and sylvatic reservoirs from Paraná state, Southern Brazil, were studied using the randomly amplified polymorphic DNA (RAPD) and simple sequence repeat-anchored polymerase chain reaction amplification (SSR-PCR) techniques. Sylvio and Esmeraldo stocks were used as reference for T. cruzi I and II, respectively. The DNA was amplified using three different primers for RAPD and (CA)8RY primer for SSRPCR. Gel analyses were scored by eye for a numerical taxonomy analysis based on the proportion of shared bands and by employing computer programs. The phenograms showed the existence of two distinct genetic groups: one containing the strains from chronic chagasic patients grouped with Esmeraldo and the other with the strains from triatomines and sylvatic reservoirs grouped with Sylvio. The existence of two phylogenetic groups of T. cruzi in Paraná state, Southern Brazil, is described for the first time.