Experimental infection of two South American reservoirs with four distinct strains ofTrypanosoma cruzi

Abstract

SUMMARY Trypanosoma cruzi (Tc), the causative agent of Chagas disease, is a diverse species with 2 primary genotypes, TcI and TcII, with TcII further subdivided into 5 subtypes (IIa–e). This study evaluated infection dynamics of 4 genetically and geographically diverse T. cruzi strains in 2 South American reservoirs, degus (Octodon degus) and grey short-tailed opossums (Monodelphis domestica). Based on prior suggestions of a genotype-host association, we hypothesized that degus (placental) would more readily become infected with TcII strains while short-tailed opossums (marsupial) would be a more competent reservoir for a TcI strain. Individuals (n = 3) of each species were intraperitoneally inoculated with T. cruzi trypomastigotes of TcIIa [North America (NA)-raccoon (Procyon lotor) origin], TcI [NA-Virginia opossum (Didelphis virginiana)], TcIIb [South America (SA)-human], TcIIe (SA-Triatoma infestans), or both TcI and TcIIa. Parasitaemias in experimentally infected degus peaked earlier (7–14 days post-inoculation (p.i.)) compared with short-tailed opossums (21–84 days p.i.). Additionally, peak parasitaemias were higher in degus; however, the duration of detectable parasitaemias for all strains, except TcIIa, was greater in short-tailed opossums. Infections established in both host species with all genotypes, except for TcIIa, which did not establish a detectable infection in short-tailed opossums. These results indicate that both South American reservoirs support infections with these isolates from North and South America; however, infection dynamics differed with host and parasite strain.

Ecological host fitting of Trypanosoma cruzi TcI in Bolivia: mosaic population structure, hybridization and a role for humans in Andean parasite dispersal

“…These biological features may predispose these hosts to multiplicity of infection which will be directly related to intensity and efficiency of parasite transmission and duration and course of disease (Roellig et al . 2010; Nouvellet et al . 2013).…”

Molecular characterization of Trypanosoma cruzi Mexican strains and their behavior in the mouse experimental model

“…Roellig et al 41 observed that the genotypes of parasites belonging to groups TcI and TcIIe (now TcVI) are characterized by maintaining subpatent parasitaemia during the chronic phase and infecting Rhodnius prolixus. According to these authors, maintenance of the sylvatic cycle of T. cruzi depends on competitive vectors that find infected hosts.…”

Trypanosoma cruzi and Chagas' Disease in the United States

“…The genus Philander also displays a more severe inflammatory response to T. cruzi (162,163). Experimental inoculation of Monodelphis domestica with TcI, TcII, and TcVI strains resulted in infections, but a North American TcIV isolate failed to establish an infection (242). Collectively, these data suggest that the marsupial genera diverged before the establishment of host relationships with T. cruzi and that utilization of different ecological niches resulted in distinct T. cruzi lineage transmission patterns (163).…”