Trypanosomatid Richness in Wild and Synanthropic Small Mammals from a Biological Station in Rio de Janeiro, Brazil

Abstract

Trypanosomatids are diverse and can infect several host species, including small mammals (rodents and marsupials). Between 2012 and 2014, 91 small mammals were surveyed for trypanosomatid infection in the Estação Biológica FIOCRUZ Mata Atlântica (EFMA), an Atlantic Forest area in Rio de Janeiro that presents different levels of conserved and degraded areas. Blood, skin, liver, and spleen samples were submitted to parasitological, serological, and molecular assays to detect the infection and determine the taxonomic status of their parasites. Sixty-eight individuals (74.7%; n = 91) were infected by trypanosomatids, including fourteen mixed infected by different trypanosomatid parasites. These hosts were infected by: T. cruzi DTU TcI (n = 12), T. cruzi DTU TcIV (n = 2), T. janseni (n = 15), T. dionisii (n = 1), and T. rangeli A (n = 1) detected in blood or tissue cultures, in addition to T. cruzi DTU TcI (n = 9) and Leishmania sp. (n = 1) only by the molecular diagnosis. Serological diagnosis was positive in 38 (71.6%) individuals for T. cruzi, the same amount for Leishmania spp., and 23 (43.3%) individuals were mixed infected. These data indicate a remarkable richness of trypanosomatid species/genotypes infecting small mammals, even in a disturbed area with low mammal species diversity—as is the case of the EFMA—reinforcing the generalist aspect of these parasites.

Trypanosoma Species in Small Nonflying Mammals in an Area With a Single Previous Chagas Disease Case

“…The high rates of marsupials infected by T. janseni observed in different Brazilian biomes reinforce that the genus Didelphis is one of the oldest hosts of parasite species from the T. cruzi clade and may also be the ancient host of T. janseni (Lopes et al, 2018;Rodrigues et al, 2019). However, T. janseni was demonstrated to be adaptable to other mammalian taxa, since it was identified in two rodent species (A. cursor and E. russatus) in this study and in Berbigier et al (2021), and it was found infecting a dog, as demonstrated by PCR of blood clot samples (Malavazi et al, 2020).…”

“…In this study, T. janseni was found to infect D. aurita and two rodent species: A. cursor and E. russatus. Three points suggest a possible biological diversity of T. janseni: i) by the ability to grow on NNN + LIT medium of some isolates in contrast to others probably representing a different genetic makeup (Berbigier et al, 2021); ii) sequencing showed a SNP, and the phylogenetic tree separated T. janseni into two groups. Obviously, the sequenced gene fragment is very small, and we would need whole 18S rDNA sequencing to evaluate this heterogeneity.…”