Rickettsia parkeri in the Pampa biome of southern Brazil: Isolation, molecular characterization, and serological evidence of canine infection

Autor(es)

Weck, Barbara ^{[1, 2]} ; Krawczak, Felipe S. ^[3] ; Costa, Francisco B. ^[4] ; Dall'Agnol, Bruno ^[2] ; Marcili, Arlei ^[5] ; Reck, Jose ^[2] ; Labruna, Marcelo B. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Med Vet Prevent & Saude Anim, Sao Paulo - Brazil

^[2] Inst Pesquisas Vet Desiderio Finamor IPVDF, Ctr Pesquisa Saude Anim, Eldorado Do Sul, RS - Brazil

^[3] Univ Fed Goias, Escola Vet & Zootecnia, Setor Med Vet Prevent, Goiania, Go - Brazil

^[4] Univ Estadual Maranhao, Dept Patol, Med Vet, Sao Luis, Maranhao - Brazil

^[5] Univ Santo Amaro, Med & Bem Estar Anim, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS; v. 22, DEC 2020.
• Citações Web of Science: 1

Resumo

In this work we performed a field study in a spotted fever-endemic area of the Pampa biome in Rio Grande do Sul, the southernmost state of Brazil (Rosario do Sul municipality), with the aim to evaluate the serological status of dogs for spotted fever group (SFG) rickettsiae, to attempt the isolation rickettsiae from A. tigrinum ticks, and to further perform a multi-genic molecular characterization of the rickettsial isolate. For this purpose, we collected blood serum samples and ticks from 18 rural dogs during 2016-2017. By immunofluorescence assay, all 18 dogs (100%) reacted serologically to SFG rickettsiae, with highest endpoint titers to R. parkeri, suggesting that at least part of these dogs have been infected by R. parkeri. Among 23 ticks collected from the dogs (13 A. tigrinum and 10 Rhipicephalus sanguineus sensu stricto), 46% (6/13) A. tigrinum contained DNA of R. parkeri, which was successfully isolated in Vero cell culture from one of these ticks. Partial sequences of five genes (gltA, ompA, virB4, dnaA, dnaK) and 3 intergenic spacers (mppA-purC, rrl-rrf-ITS, rpmE-tRNA(fMet)) were generated from this rickettsial isolate, and were all 100% identical to corresponding sequences of R. parkeri s.s. We provide the first report of a viable isolate of R. parkeri from A. tigrinum, confirming that this isolate belongs to the strain R. parkeri s.s., as it has already been demonstrated for other two tick species of the Amblyomma maculatum species complex (A. maculatum and Amblyomma triste). (AU)

• Processo FAPESP: 17/04249-4 - Pesquisa de agentes transmitidos por carrapatos (Anaplasma spp, Babesia spp, Borrelia spp, Ehrlichia spp e Hepatozoon spp) em pequenos mamíferos e seus carrapatos em áreas endêmicas e não endêmicas para febre maculosa no estado de São Paulo, Brasil.
• Beneficiário: Bárbara Conte Weck
• Modalidade de apoio: Bolsas no Brasil - Doutorado