Molecular survey of tick-borne pathogens in small mammals from Brazilian Amazonia.

Ana Cláudia Colle,Ravena Fernanda Braga De Mendonça,Maerle Oliveira Maia,Daniel Moura De Aguiar,Rogério Vieira Rossi,Sebastián Muñoz-Leal,Leodil Da Costa Freitas,Marcelo Bahia Labruna,Rute Witter,Richard De Campos Pacheco,Arlei Marcili

doi:10.1590/s1984-29612019086

Abstract

Small non-volant mammals (marsupials and small rodents) were captured at three different timepoints from 23 forest fragments across three municipalities (Alta Floresta, Sinop and Cláudia) covering the Amazonian biome of the Mato Grosso State in Midwestern Brazil. The animal tissues (liver and spleen) and blood were screened using molecular tools for the detection of Babesia, Coxiella, Cytauxzoon, Hepatozoon, Theileria, and Anaplasmataceae agents. A total of 230 specimens (78 rodents and 152 marsupials) were trapped. Hepatozoon and Piroplasmorida agents were detected in the common opossums (Didelphis marsupialis). In turn, all samples (blood, liver, or spleen) collected from the small mammals were negative for the genus Coxiella and the family Anaplasmataceae, as detected by polymerase chain reaction (PCR). Phylogenetic analyses inferred from partial sequences of the 18S rRNA gene highlighted the occurrence of new Hepatozoon and Piroplasmorida haplotypes. Future studies determining the role of common opossum (D. marsupialis) in the epidemiological cycles of Hepatozoon and Babesia under natural conditions in the Amazonian biome are necessary.

Highlights

The interactions between animals, humans, and the environment in which both live are currently recognized as the drivers for a unified health concept, contemporary known as ‘One Health’ (ROBERTSON et al, 2014)
Future studies determining the role of common opossum (D. marsupialis) in the epidemiological cycles of Hepatozoon and Babesia under natural conditions in the Amazonian biome are necessary
Previous studies performed on reptiles, birds, and mammals exposed a variety of genetically distinct organisms of the Anaplasmataceae family circulating in the Amazonian wildlife under natural conditions, which included those of the Cavia sp. (Rodentia: Caviidae) and Marmosa demerarae (Didelphimorphia: Didelphidae) (SOARES et al, 2017a)

Summary

Introduction

The interactions between animals, humans, and the environment in which both live are currently recognized as the drivers for a unified health concept, contemporary known as ‘One Health’ (ROBERTSON et al, 2014). Small mammals are widely distributed vertebrates and ticks constitute common parasites (DURDEN, 2006). A wide variety of vertebrate pathogens (especially certain viruses, bacteria and protozoa) evolved strategies to thrive in transmission cycles that include ticks and associated small mammals hosts (DURDEN & KEIRANS, 1996; SONENSHINE et al, 2002; DURDEN, 2006). Apart from several Candidatus taxa, this family of bacteria currently comprises four recognized genera, namely Anaplasma, Ehrlichia, Neorickettsia, and Wolbachia, of which, the first two are recognized as tick-borne pathogens with relevance in veterinary and public health (DUMLER et al, 2001). The gamma-proteobacterium Coxiella burnetii is the causative agent of Q fever/coxiellosis and chronic endocarditis in humans globally (MAURIN & RAOULT 1999). Molecular evidence has revealed that C. burnetti infects humans in Brazil (LEMOS et al, 2011), and that wild mammals could act as natural reservoirs for this agent (ROZENTAL et al, 2017; FERREIRA et al, 2018; ZANATTO et al, 2019)

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Conclusion