title: Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
authors.affiliation: Universidade Federal de Uberlândia, Uberlândia, Minas Gerais, Brasil. marcellamgc@hotmail.comm.
authors.forename: Marcella Gonçalves
authors.initials: MG
authors.lastname: Coelho
authors.forename: Vanessa do Nascimento
authors.initials: Vdo N
authors.lastname: Ramos
authors.forename: Jean Ezequiel
authors.initials: JE
authors.lastname: Limongi
authors.forename: Elba Regina Sampaio
authors.initials: ER
authors.lastname: de Lemos
authors.forename: Alexandro
authors.initials: A
authors.lastname: Guterres
authors.forename: Sócrates Fraga
authors.initials: SF
authors.lastname: da Costa Neto
authors.forename: Tatiana
authors.initials: T
authors.lastname: Rozental
authors.forename: Cibele Rodrigues
authors.initials: CR
authors.lastname: Bonvicino
authors.forename: Paulo Sérgio
authors.initials: PS
authors.lastname: D'Andrea
authors.forename: Jonas
authors.initials: J
authors.lastname: Moraes-Filho
authors.forename: Marcelo Bahia
authors.initials: MB
authors.lastname: Labruna
authors.forename: Matias Pablo Juan
authors.initials: MP
authors.lastname: Szabó
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001938:Brazil / Q000453:epidemiology; D019084:Fluorescent Antibody Technique, Indirect; D008322:Mammals; D012281:Rickettsia / Q000276:immunology*; D012282:Rickettsia Infections / Q000453:epidemiology / Q000662:veterinary*; D012376:Rodent Diseases / Q000453:epidemiology*; D016036:Seroepidemiologic Studies
chemical_list: D000907:Antibodies, Bacterial