Serological detection and molecular characterization of agents transmitted by arthropod vectors in wild and domestic animals in the region of the southern mato grosso Pantanal

Author(s)

Keyla Carstens Marques de Sousa

• Document type: Doctoral Thesis
• Press: Jaboticabal. 2017-03-29.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2017-02-03
• Advisor: Marcos Rogério André

Abstract

The diseases transmitted by arthropods have been recently studied in Brazilian wildlife, which can act as hosts for vectors and pathogens, many of which have zoonotic potential. The present work aimed to investigate the occurrence of tick-borne agents (Anaplasmataceae agents, Bartonella spp., hemotropic mycoplasmas, Rickettsia spp., Hepatozoon spp. and piroplasms) in wild animals, domestic dogs and their respective ectoparasites, in southern Pantanal region, central-western Brazil, by serological and molecular assays. For this reason, 31 Nasua nasua, 78 Cerdocyon thous, seven L. pardalis, 42 dogs, 110 rodents and 30 marsupials were captured. The ticks collected (1582) from animals belonged to the species Amblyomma sculptum, Amblyomma parvum, Amblyomma ovale, Amblyomma tigrinum, Rhipicephalus microplus, Rhipicephalus sanguineus sensu lato and Amblyomma auricularium. Additionally, 80 Polygenis (Polygenis) bohlsi bohlsi fleas were collected. Overall, 14 (17.9%) C. thous, seven (16.6%) dogs and one (3.2%) N. nasua were seroreactive (titer≥80) to Ehrlichia canis, with titers ranging from 80 to 1280. No animal showed to be seroreactive for A. phagocytophilum antigen. Nine dogs, two C. thous, one N. nasua, eight rodents, five marsupials and one P. (P.) b. bohlsi pool were positive for Ehrlichia spp. All positive dogs and the only P. (P.) b. bohlsi pool positive for Ehrlichia spp. were also positive in specific E. canis-qPCR based on dsb gene. Seven N. nasua, two dogs, one C. thous, one L. pardalis, four rodents, three marsupials, 15 A. sculptum, two A. ovale, two A. parvum and one Amblyomma larvae pool were positive for Anaplasma spp. Co-positivity or co-seropositivity for Ehrlichia spp. and Anaplasma spp. was observed in two dogs, one N. nasua, one C. thous and two marsupials. Thirty-five rodents and three P. (P.) b. bohlsi flea pools, showed to be positive to Bartonella spp. in the molecular assays. The phylogenetic analysis revealed that at least two different genotypes are circulating among the rodents sampled in the Pantanal biome. Partial results suggest that the flea P. (P.) b. bohlsi may be acting as a possible Bartonella vector in this region. Twenty-four N. nasua, three C. thous, two dogs and one rodent, were positive for Mycoplasma spp. Phylogenetic analysis indicated that dogs, C. thous and N. nasua appear to share the same Mycoplasma spp. species, closely related to M. haemocanis / M. haemofelis and probably a new genotype of Mycoplasma spp. is circulating among the N. nasua and C. thous sampled in the Pantanal biome. Overall, 27 (64.2%) dogs, 59 (75.6%) C. thous and six (85.7%) L. pardalis were seroreactive to at least one Rickettsia species. For 17 (40.4%) dogs, 33 (42.3%) C. thous, and two (33.3%) L. pardalis, homologous reactions to Rickettsia amblyommatis were suggested. One hundred and sixteen ticks (93 A. parvum, 14 A. sculptum, three A. auricularim and six Amblyomma larvae pools) and one blood sample obtained from C. thous showed positive results for Rickettsia spotted fever group species. The sequenced samples obtained from A. parvum ticks showed to be closely related to 'Candidatus Rickettsia andeanae'. A high occurrence of Hepatozoon was found in carnivores (C. thous [91.02%], dogs [45.23%], N. nasua [41.9%] and L. pardalis [71.4%]), however no arthropod showed positive results. Additionally, twenty-four rodents and a marsupial also showed positivity to Hepatozoon spp. Based on phylogenetic analysis, C. thous, L. pardalis, N . nasua, dogs, rodents and marsupials appear not to share the same of Hepatozoon species. Seven dogs, one C. thous, five L. pardalis, three N. nasua, six rodents, eight A. parvum, two A. sculptum and one A. ovale were positive for piroplasmids-PCR assays. Genotypes closely related to Babesia vogeli were detected in six dogs and five rodents. While genotypes closely related to Babesia caballi were detected in one C. thous, one dog, one A. ovale and one A. sculptum, genotypes closely related to Babesia bigemina and Babesia bovis were detected in four A. parvum ticks. Four sequences obtained from A. parvum, three N. nasua and one wild rodent were closely related to Theileria equi. Lastly, Cytauxzoon spp. was detected in four L. pardalis. The present work shows the occurrence of vector-borne agents in wild and domestic animals in southern mato grosso Pantanal. (AU)

• FAPESP's process: 13/13186-5 - Serological detection and molecular characterization of agents transmitted by arthropod vectors in wild and domestic animals in the region of the southern Mato Grosso Pantanal
• Grantee: Keyla Carstens Marques de Sousa
• Support Opportunities: Scholarships in Brazil - Doctorate