Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil

  • Marcella Gonçalves Coelho Universidade Federal de Uberlândia, Uberlândia, Minas Gerais, Brasil
  • Vanessa do Nascimento Ramos Universidade Federal de Uberlândia, Uberlândia, Minas Gerais, Brasil
  • Jean Ezequiel Limongi Universidade Federal de Uberlândia, Uberlândia, Minas Gerais, Brasil
  • Elba Regina Sampaio de Lemos Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
  • Alexandro Guterres Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
  • Sócrates Fraga da Costa Neto Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
  • Tatiana Rozental Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
  • Cibele Rodrigues Bonvicino Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
  • Paulo Sérgio D'Andrea Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
  • Jonas Moraes-Filho Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brasil
  • Marcelo Bahia Labruna Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brasil
  • Matias Pablo Juan Szabó Universidade Federal de Uberlândia, Uberlândia, Minas Gerais, Brasil
Keywords: Rickettsia, Ixodidae, Rodentia, Marsupialia, seroepidemiologic studies, Brazil

Abstract

Introduction: Sources of pathogenic Rickettsia in wildlife are largely unknown in Brazil. In this work, potential tick vectors and seroreactivity of small mammals against four spotted-fever group Rickettsia (R. rickettsii, R. parkeri, R. amblyommii and R. rhipicephali) and Rickettsia bellii from peri-urban areas of Uberlândia, a major town in Brazil, are described for the first time.

Methodology: Small mammals were captured and blood samples collected. Ticks were collected from the surface of the host and the environment and posteriorly identified. Reactivity of small mammal sera to Rickettsia was tested by indirect immunofluorescence assay (IFA) using crude antigens from five Brazilian Rickettsia isolates.

Results: Information was obtained from 416 small mammals (48 Marsupialia and 368 Rodentia). Forty-eight animals were parasitized and two tick species, Ixodes loricatus and Amblyomma dubitatum, were found on several host species, with a few tick-host relationships described for the first time. From the 416 tested sera, 70 reacted to at least one Rickettsia antigen (prevalence of 16.8%) and from these, 19 (27.1%) reacted to two or more antigens. Seroprevalence was higher for marsupials (39.6%) than for rodents (13.8%). Marsupial and Rhipidomys spp. sera reacted mainly (highest seroprevalence and titers) to R. bellii, and that of Necromys lasiurus mainly to R. rickettsii.

Conclusions: Although the serologic assays poorly discriminate between closely related spotted-fever group Rickettsia, the observed small mammal seroreactivity suggests the circulation of Rickettsia in the peri-urban area of Uberlândia, albeit at low levels.

Published
2016-03-31
How to Cite
1.
Coelho MG, Ramos V do N, Limongi JE, de Lemos ERS, Guterres A, da Costa Neto SF, Rozental T, Bonvicino CR, D’Andrea PS, Moraes-Filho J, Labruna MB, Szabó MPJ (2016) Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil. J Infect Dev Ctries 10:275-282. doi: 10.3855/jidc.7084
Section
Original Articles