Trypanosoma cruzi DTU II coinfection with bacteria producing prolonged cutaneous lesion in a healthy young male

ABSTRACT Chagas disease (CD) is a neglected tropical disease caused by Trypanosoma cruzi and is genetically classified in six discrete typing units (DTUs). The isolates reported in Mexico are generally associated with DTU I. We presented a case of a prolonged cutaneous lesion in a Mexican man, caused by DTU II in coinfection with Bacillus velezensis and Corynebacterium sp. The patient assessment included a complete clinical history, physical exam, laboratory tests, and a skin biopsy. In the facial tissues, intracellular parasites were revealed. The PCR tests were positive for T. cruzi in tissue and blood samples. DNA satellite sequencing was correlated with the DTU II. The initial serological tests reported negative results. However, four months later, two serological tests reported positive results. These exams were performed in different health centers. Mexico is considered an endemic area for CD; nevertheless, this is just the second cutaneous case associated with a DTU different from DTU-I noted in this country. From an ecological point of view, this fact suggests a geographical expansion of DTU II and an association with atypical skin manifestations. Further studies should be conducted to understand this exciting association between DTU-II and prolonged cutaneous expression in humans.

Sympatry influence in the interaction of Trypanosoma cruzi with triatomine

Abstract INTRODUCTION: Trypanosoma cruzi, the etiologic agent of Chagas disease, is widely distributed in nature, circulating between triatomine bugs and sylvatic mammals, and has large genetic diversity. Both the vector species and the genetic lineages of T. cruzi present a varied geographical distribution. This study aimed to verify the influence of sympatry in the interaction of T. cruzi with triatomines. Methods: The behavior of the strains PR2256 (T. cruzi II) and AM14 (T. cruzi IV) was studied in Triatoma sordida (TS) and Rhodnius robustus (RR). Eleven fifth-stage nymphs were fed by artificial xenodiagnosis with 5.6 × 103 blood trypomastigotes/0.1mL of each T. cruzi strain. Every 20 days, their excreta were examined for up to 100 days, and every 30 days, the intestinal content was examined for up to 120 days, by parasitological (fresh examination and differential count with Giemsa-stained smears) and molecular (PCR) methods. Rates of infectivity, metacyclogenesis and mortality, and mean number of parasites per insect and of excreted parasites were determined. RESULTS: Sympatric groups RR+AM14 and TS+PR2256 showed higher values of the four parameters, except for mortality rate, which was higher (27.3%) in the TS+AM14 group. General infectivity was 72.7%, which was mainly proven by PCR, showing the following decreasing order: RR+AM14 (100%), TS+PR2256 (81.8%), RR+PR2256 (72.7%) and TS+AM14 (36.4%). CONCLUSIONS: Our working hypothesis was confirmed once higher infectivity and vector capacity (flagellate production and elimination of infective metacyclic forms) were recorded in the groups that contained sympatric T. cruzi lineages and triatomine species.

Determinación del grado de infestación e infección de vectores de la enfermedad de Chagas en la comunidad de Huayhuasi (Mecapaca) / Determination of the degree of infestation and infection of vectors of Chagas disease in the community of Huayhuasi (Mecapaca)

Los trabajos realizados de trampeo y captura de triatominos (que son los insectos vectores de la enfermedad de Chagas) en zonas silvestres de los alrededores de la localidad de Huayhuasi, municipio de Mecapaca en el departamento de La Paz. Se colocaron 50 trampas en lugares estratégicos escogidos de acuerdo a las características del área de estudio. De las 50 trampas, en 9 trampas se lograron atrapar a los triatominos, lo que representa el 4.5% de infestación de la zona de estudio. Se capturaron a 13 insectos (7 ninfas de diferentes estadíos y 6 adultos). Las características morfológicas de los insectos fueron las típicas del Triatoma infestans. En el examen en fresco de las deyecciones de los 6 especímenes adultos capturados, en 4 de ellos se detectó presencia del parásito Trypanosoma cruzi, lo cual demuestra un 67% de infección, porcentaje bastante significativo en consideración a la cercanía de estos lugares infestados a las zonas urbanas del municipio de Mecapaca. Los parásitos que los especímenes portaban, fueron aislados y cultivados en medio de cultivo LIT (Liver Infusion Tryptose) suplementado con 10% de suero bovino fetal e incubados en estufa a 26°C. El análisis del ADN extraído de los parásitos, ha revelado la DTU (Discrete Typing Unit) correspondiente al linaje TcI.

Trapping and capture of triatomines (which are the insect's vectors of Chagas' disease) were carried out in wild areas around the town of Huayhuasi, municipality of Mecapaca, in the department of La Paz. 50 traps were placed in strategic places chosen according to the characteristics already established. Of the 50 traps, nine traps managed to trap the triatomines, representing 4.5% of infestation in the study area. 13 insects (7 nymphs of different stages and 6 adults) were captured. The morphological characteristics of the insects were typical of Triatoma infestans. In the fresh examination of the excrement of the six captured adult specimens, in 4 of them the presence of the parasite Trypanosoma cruzi was detected, which shows a 67% infection, a very significant percentage considering the proximity of these infested places to the Urban areas of the municipality of Mecapaca. The parasites that the specimens carried were isolated and cultured in LIT (Liver Infusion Triptose) medium supplemented with 10% fetal bovine serum and incubated in an oven at 26 °C. Analysis of the DNA extracted from the parasites has revealed the DTU corresponding to the Tc I lineage.

Infection with Trypanosoma cruzi TcII and TcI in free-ranging population of lion tamarins (Leontopithecus spp): an 11-year follow-up

Here, we present a review of the dataset resulting from the 11-years follow-up of Trypanosoma cruzi infection in free-ranging populations of Leontopithecus rosalia (golden lion tamarin) and Leontopithecus chrysomelas (golden-headed lion tamarin) from distinct forest fragments in Atlantic Coastal Rainforest. Additionally, we present new data regarding T. cruzi infection of small mammals (rodents and marsupials) that live in the same areas as golden lion tamarins and characterisation at discrete typing unit (DTU) level of 77 of these isolates. DTU TcII was found to exclusively infect primates, while TcI infected Didelphis aurita and lion tamarins. The majority of T. cruzi isolates derived from L. rosalia were shown to be TcII (33 out 42) Nine T. cruzi isolates displayed a TcI profile. Golden-headed lion tamarins demonstrated to be excellent reservoirs of TcII, as 24 of 26 T. cruzi isolates exhibited the TcII profile. We concluded the following: (i) the transmission cycle of T. cruzi in a same host species and forest fragment is modified over time, (ii) the infectivity competence of the golden lion tamarin population fluctuates in waves that peak every other year and (iii) both golden and golden-headed lion tamarins are able to maintain long-lasting infections by TcII and TcI.