Molecular detection of Hepatozoon spp. in domestic dogs and wild mammals in southern Pantanal, Brazil with implications in the transmission route

Abstract

Hepatozoon parasites comprise intracellular apicomplexan parasites transmitted to vertebrate animals by ingestion of arthropods definitive hosts. The present work aimed to investigate the occurrence of Hepatozoon spp. in wild animals, domestic dogs and their respective ectoparasites, in southern Pantanal region, central-western Brazil, by molecular techniques. Between August 2013 and March 2015, 31 coatis (Nasua nasua), 78 crab-eating foxes (Cerdocyon thous), seven ocelots (Leopardus pardalis), 42 dogs (Canis lupus familiaris), 110 wild rodents (77 Thichomys fosteri, 25 Oecomys mamorae, and 8 Clyomys laticeps), 30 marsupials (14 Thylamys macrurus, 11 Gracilinanus agilis, 4 Monodelphis domestica and 1 Didelphis albiventris), and 1582 ticks and 80 fleas collected from the sampled animals were investigated. DNA samples were submitted to PCR assays for Hepatozoon spp. targeting 18S rRNA gene. Purified amplicons were directly sequenced and submitted to phylogenetic analysis. A high prevalence of Hepatozoon among carnivores (C. thous [91.02%], dogs [45.23%], N. nasua [41.9%] and L. pardalis [71.4%]) was found. However, ticks and fleas were negative to Hepatozoon PCR assays. By phylogenetic analysis based on 18S rRNA sequences, Hepatozoon sequences amplified from crab-eating foxes, dogs, coatis and ocelots clustered with sequences of H. canis, H. americanum and H. felis. The closely related positioning of Hepatozoon sequences amplified from wild rodents and T. macrurus marsupial to Hepatozoon from reptiles and amphibians suggest a possible transmission of those Hepatozoon species between hosts by ectoparasites or by predation. Hepatozoon haplotypes found circulating in wild rodents seem to present a higher degree of polymorphism when compared to those found in other groups of animals. Although rodents seem not to participate as source of Hepatozoon infection to wild carnivores and domestic dogs, they may play an important role in the transmission of Hepatozoon to reptiles and amphibians in Pantanal biome.

Occurrence and molecular characterization of hemoplasmas in domestic dogs and wild mammals in a Brazilian wetland

“…The Pantanal is the largest Neotropical floodplain, being well known for its rich biodiversity. Two well-defined seasons are recognized in the studied region: a rainy summer (October to March) and a dry winter (April to September) (Sousa et al, 2017).…”

“…Forty-two blood samples from domestic dogs cohabiting the same studied area were also collected. All animal captures were in accordance with the licenses obtained from the Brazilian Government Institute for Wildlife and Natural Resources Care (IBAMA) (license numbers38145, 38787-2) and endorsed by the Ethics Committee of FCAV/UNESP University (Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Câmpus Jaboticabal) n°006772/13 (Sousa et al, 2017).…”

Ectoparasitos Em Cães De Áreas Peri-Rurais Do Município De Rio Branco, Acre, Amazônia Ocidental

“…O parasitismo de Amblyomma ovale nos cães de áreas peri-rurais do munícipio de Rio Branco, AC, os predispõem a serem acometidos por hepatozoonose canina uma vez que Rubini et al (2009) afirmam que A. ovale é o vetor potencial de hepazoonose em cães rurais. Além do mais, Sousa et al (2017) verificaram a alta prevalência de Hepatozoon entre carnívoros amostrados no Pantanal e a ocorrência de infestação de A. ovali em animais silvestres.…”

Hepatozoon caimani in Caiman crocodilus yacare (Crocodylia, Alligatoridae) from North Pantanal, Brazil

“…Regarding the molecular characterization based on rDNA coding regions, such as that used in the present study (18S rRNA), although highly conserved and used frequently in molecular characterization of Hepatozoon spp. in several hosts (ANDRÉ et al, 2010;BORTOLI et al, 2011;MOÇO et al, 2012;O'DWYER et al, 2013;SOARES et al, 2017a;SOUSA et al, 2017), this target sequence may not be suitable for phylogenetic inferences of parasites which share some of intraspecific divergences (MOÇO et al, 2012), preventing attempts to differentiate those species. The search for new targets genes which allow a better phylogenetic differentiation of this group of parasites are much needed as an attempt to elucidate the diversity of Hepatozoon species that parasitize reptiles.…”