Trypanosomatids in Small Mammals of an Agroecosystem in Central Brazil: Another Piece in the Puzzle of Parasite Transmission in an Anthropogenic Landscape.

Brandão Brandão,Roque Roque,Lemos Lemos,Carvalhaes Carvalhaes,Xavier Xavier,Cássia-Pires Cássia-Pires,Azevedo Azevedo,Jansen Jansen,D’andrea D’Andrea

doi:10.3390/pathogens8040190

Abstract

We surveyed infection by Trypanosoma spp. and Leishmania spp. in small wild mammals from Cumari, Goiás State aiming to investigate the diversity of trypanosomatid in a modified landscape of the Brazilian Cerrado (and possible infection overlapping with canids from the same area). Blood, skin, spleen, and liver samples were collected for parasitological, serological, and molecular assays. Gracilinanus agilis was the most abundant species (N = 70; 48.6%) and it was the only one with patent parasitemia. Characterization by mini-exon and 18SrDNA targets were achieved in 7/10 hemocultures with positive fresh blood examination, which confirmed the T. cruzi infection by Discrete Typing Units (DTU) TcI in single (N = 2) and mixed infections with other DTUs (N = 5). T. rangeli and T. dionisii were detected in skin fragments from Didelphis albiventris and Oecomys cleberi, respectively. G. agilis were found to be infected by L. braziliensis and L. guyanensis, while Leishmania sp. DNA was detected in the liver of Oligoryzomys nigripes and Calomys expulsus. Subpatent infection by T. cruzi and Leishmania sp. was serologically detected in 15% and 9% of the small mammal fauna, respectively. Small mammals from Cumari are included in T. cruzi and Leshmania spp. transmission cycles, showing a higher diversity of trypanosomatid species and/or genotypes than that observed in canids of the same agroecosystem.

Highlights

Trypanosoma cruzi and Leishmania spp. (Trypanosomatida; Trypanosomatidae) are enzootic parasites that are maintained in the Americas by dozens of species of mammals and transmitted by hematophagous vector insects, triatomines from the Reduviidae family, and female sandflies fromPathogens 2019, 8, 190; doi:10.3390/pathogens8040190 www.mdpi.com/journal/pathogensLutzomyia genus, respectively [1,2]
A greater richness of rodents than marsupials was registered for dry seasons (p = 0.016), whereas no difference was detected for wet seasons
We demonstrated the small mammal fauna of the Limoeiro region and the most abundant species were Gracilinanus agilis, Calomys expulsus, Oecomys cleberi, and Rhipidomys macrurus

Summary

Introduction

Trypanosoma cruzi and Leishmania spp. (Trypanosomatida; Trypanosomatidae) are enzootic parasites that are maintained in the Americas by dozens of species of mammals and transmitted by hematophagous vector insects, triatomines from the Reduviidae family, and female sandflies fromPathogens 2019, 8, 190; doi:10.3390/pathogens8040190 www.mdpi.com/journal/pathogensLutzomyia genus, respectively [1,2]. T. cruzi is the etiological agent of Chagas disease and six Discrete Typing Units (DTU) are currently recognized in this parasite: TcI to TcVI, besides Tcbat, a seventh DTU described in bats [3,4]. Despite proposed attempts to correlate T. cruzi subpopulations with host species, geographic distribution, and/or human disease, it has not yet been possible to detect any unequal association [5]. Leishmania spp. currently comprises more than 30 species, some of which are responsible for distinct clinical forms of human leishmaniasis as zoonotic diseases with high public health impact [6,7]. Knowledge of leishmaniasis has improved in recent decades, little is known regarding the spectrum of host species (mammals and vectors) of this parasite in nature [13]

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