Trypanosoma cruzi I genotype among isolates from patients with chronic Chagas disease followed at the Evandro Chagas National Institute of Infectious Diseases (FIOCRUZ, Brazil)

ABSTRACT INTRODUCTION: Trypanosoma cruzi is the etiologic agent of Chagas disease in humans, mainly in Latin America. Trypanosome stocks were isolated by hemoculture from patients followed at Evandro Chagas National Institute of Infectious Diseases (FIOCRUZ) and studied using different approaches. METHODS: For species and genotype identification, the stocks were analyzed by parasitological techniques, polymerase chain reaction assays targeted to specific DNA sequences, isoenzyme patterns, besides sequencing of a polymorphic locus of TcSC5D gene (one stock). RESULTS: The isolates presented typical T. cruzi morphology and usually grew well in routine culture media. Metacyclic trypomastigotes were found in cultures or experimentally infected Triatoma infestans. All isolates were pure T. cruzi cultures, presenting typical 330-bp products from kinetoplast DNA minicircles, and 250 or 200-bp amplicons from the mini-exon non-transcribed spacer. Their genetic type assignment was resolved by their isoenzyme profiles. The finding of TcI in one asymptomatic patient from Paraíba was confirmed by the sequencing assay. TcVI was found in two asymptomatic individuals from Bahia and Rio Grande do Sul. TcII was identified in six patients from Pernambuco, Bahia and Minas Gerais, who presented different clinical forms: cardiac (2), digestive with megaesophagus (1), and indeterminate (3). CONCLUSIONS: The main T. cruzi genotypes found in Brazilian chronic patients were identified in this work, including TcI, which is less frequent and usually causes asymptomatic disease, unlike that in other American countries. This study emphasizes the importance of T. cruzi genotyping for possible correlations between the parasite and patient’ responses to therapeutic treatment or disease clinical manifestations.

Characterization of Leishmania infantum species in dogs from the urban area of Cuiabá, State of Mato Grosso, Brazil / Caracterização da espécie Leishmania infantum em cães de área urbana de Cuiabá, Estado do Mato Grosso

INTRODUCTION: Visceral leishmaniasis presents urban behavior in some Brazilian cities, with domestic dogs as the main infection source. In Cuiabá, MT, canine visceral leishmaniasis was diagnosed and characterized as recommended by the Ministry of Health. METHODS: Biological samples from suspected canine carriers were analyzed by the isoenzyme electrophoresis technique. The 6PGDH enzyme and reference strain IOC/L0566 (MHOM/BR/1975/M2903) of Leishmania (Leishmania) infantum was used as one of the controls. RESULTS: Electrophoresis analysis revealed that the canine isolates belonged to the species L. (L.) infantum. CONCLUSIONS: The authors emphasize the importance of species characterization, particularly in areas of mixed infection like Cuiabá.

INTRODUÇÃO: A leishmaniose visceral apresenta comportamento urbano em algumas cidades brasileiras, sendo os cães domésticos as principais fontes de infecção. Em Cuiabá-MT, a leishmaniose visceral canina foi diagnosticada e caracterizada, como recomendação do Ministério da Saúde. MÉTODOS: Amostras biológicas de cães suspeitos foram analisadas por eletroforese de isoenzimas. Foram utilizadas a enzima 6PGDH e a cepa de referência IOC/L0566 (MHOM/BR/1975/M2903) de Leishmania (Leishmania) infantum, como um dos controles. RESULTADOS: A análise eletroforética revelou que os isolados pertenciam à espécie L. (L.) infantum. CONCLUSÕES: Os autores ressaltam a importância da caracterização da espécie, principalmente em cidades com infecção mista, como Cuiabá.