Trypanosoma cruzi diversity in the Gran Chaco: Mixed infections 4 and differential host distribution of TcV and TcVI

MARÍA MERCEDES MONJE RUMI; CECILIA PÉREZ BRANDÁN; PAULA GABRIELA RAGONE; NICOLÁS TOMASINI; JUAN JOSÉ LAUTHIER; ANAHÍ ALBERTI DAMATO; RUBÉN CIMINO; VIVIANA ORELLANA; MIGUEL ÁNGEL BASOMBRÍO; PATRICIO DIOSQUE

Infection, Genetics and Evolution

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014

1567-1348

The transmission cycles of Trypanosoma cruzi in the Gran Chaco are complex networks involving domestic 33 and wild components, whose interrelationships are not well understood. Knowing the circuit of transmis- 34 sion of the different Discrete Typing Units (DTUs) of T. cruzi in the complex environment of the Chaco 35 region is relevant to understanding how the different components (reservoirs, vectors, ecotopes) interact. 36 In the present study we identified the DTUs infecting humans and dogs in two rural areas of the Gran 37 Chaco in Argentina, using molecular methods which avoid parasite culture. Blood samples of humans 38 and dogs were typified by PCR-DNA blotting and hybridization assays with five specific DNA probes 39 (TcI, TcII, TcIII, TcV and TcVI). PCR analyses were performed on seropositive human and dog samples 40 and showed the presence of T. cruzi DNA in 41.7% (98/235) and 53% (35/66) samples, respectively. The 41 identification of infective DTUs was determined in 83.6% (82/98) and 91.4% (32/35) in human and dog 42 samples, respectively. Single infections (36.7% 36/98) and a previously not detected high proportion 43 of mixed infections (47.9% 47/98) were found. In a 15.3% (15/98) of samples the infecting DTU was 44 not identified. Among the single infections TcV was the most prevalent DTU (30.6% 30/98) in human 45 samples; while TcVI (42.8% 15/35) showed the highest prevalence in dog samples. TcV/TcVI was the 46 most prevalent mixed infection in humans (32.6% 32/98); and TcI/TcVI (14.3% 5/35) in dogs. 47 Significant associations between TcV with humans and TcVI with dogs were detected. For the first time, 48 the presence of TcIII was detected in humans from this region. The occurrence of one human infected 49 whit TcIII (a principally wild DTU) could be suggested the emergence of this, in domestic cycles in the 50 Gran Chaco.