The Brazilian Spotted Fever (BSF) is a zoonotic disease caused by Rickettsia rickettsii and transmitted by ticks of the genus Amblyomma, more frequently, Amblyomma cajennense. The aim of this paper was to report the first molecular detection of R. rickettsii on R. sanguineus naturally infected in Rio de Janeiro, Brazil. Ticks were collected from dogs in a rural region of Resende municipality, Rio de Janeiro State, Brazil (22º30'9.46"S, 44º42'44.29"WO), where occurred five human cases of BSF in 2006. The ticks were identified under a stereoscopic microscope and separated in pools by stages, species and sex. DNA extraction was carried out using QIAamp DNA Mini Kit (QIAGEN®). The DNA was submitted to PCR amplification using 04 set of primers: Rr190.70p/Rr190.602n (OmpA, 532bp), BG1-21/BG2-20 (OmpB, 650bp), Tz15/Tz16 (17 kDa protein-encoding gene, 246bp) and RpCS.877p/RpCS.1258n (gltA, 381bp). PCR products were separated by electrophoresis on 1% agarose gels and visualized under ultraviolet light with ethidium bromide. PCR products of the expected sizes were purified by QIAquick® and sequenced by ABI PRISM®. The generated nucleotide sequences were edited with using Bioedit® software and compared with the corresponding homologous sequences available through GenBank, using Discontiguous Mega Blast (http://www.ncbi.nlm.nih.gov). It was confirmed R. rickettsii by sequencing of the material (GenBank FJ356230). The molecular characterization of R. rickettsii in the tick R. sanguineus emphasizes the role of dogs as carriers of ticks from the environment to home. Moreover, this result suggests that there is a considerable chance for active participation of R. sanguineus as one of tick species in the transmission of R. ricketsii to human being in the Brazilian territory.
We aimed to detect DNA of Borrelia burgdorferi in whole blood and serum samples of patients with clinical symptoms and epidemiology compatible with Brazilian Lyme-like disease. Four patients with positive epidemiological histories were recruited for the study. Blood samples were collected, screened by serologic testing by ELISA and Western blotting and molecular identification of B. burgdorferi by amplifying a fragment of the conserved gene that synthesizes the hook flagellar flgE. The results showed positive serology and for the first time, the presence of B. burgdorferi sensu lato in humans in the Midwest region of Brazil. The resulting sequences were similar to GenBank corresponding sequences of B. burgdorferi flgE gene. By neighbor-joining the phylogenetic analysis, the flgE sequence of the Brazilian strain clustered in a monophyletic group with the sequence of B. burgdorferi sensu lato under 100% bootstrap support. This study opens up promising perspectives and reinforces the need for additional studies to determine the epidemiological characteristics of the disease, as well as the impact of the prevalence of Brazilian borreliosis in Mato Grosso do Sul State, Brazil.
O presente trabalho teve como objetivo reportar a ocorrência de Borrelia spp. em culturas de células embrionárias de Boophilus microplus infectados naturalmente. Sete dias após o início de uma nova cultura primária de células embrionárias do carrapato B. microplus, incubadas a 31ºC, notou-se que as células começaram a degenerar. Ao exame em microscópio de contraste de fase detectou-se a presença de microrganismos alongado e com grande mobilidade. Lâminas de microscópio confeccionadas com amostras do sobrenadante da cultura, hemolinfa e massa de ovos, coradas pelo May Grünwald-Giemsa, permitiram a visualização de espiroquetas. O exame morfológico do microrganismo e sua visualização em B. microplus sugere ser Borrelia spp.
Borrelia burgdorferi, the agent of Lyme borreliosis, is a spirochetes transmitted by ticks to humans and animals. Its cultivation in vitro in tick cells allows studies of its biology and provides methodology for future research in Brazil, and for the isolation of Borrelia spp. We examined in vitro the characteristics of embryonic cells of Rhipicephalus microplus and Amblyomma cajennense in cell culture and investigated the suitability of embryonic cells as a substrate for cultivation of B. burgdorferi. Subcultures were prepared from primary cultures of embrionary cells of R. microplus and A. cajennense maintained in Leibovitz's (L-15) complete medium at 28 °C and 31 °C, respectively. When a monolayer had formed, the L-15 was replaced with Barbour-Stoener-Kelly medium for experiments to infect cell cultures with B. burgdorferi. After 72 hours of cultivation, the spirochetes were counted using an inverted phase contrast microscope and dark-field illumination (400×). Survival, multiplication and the adherence of B. burgdorferi for embryonic cells of R. microplus and A. cajennense were observed. B. burgdorferi cultured with embryonic cells of R. microplus grew on average to a density (final count) of 2.4 × 10 7 spirochetes/mL, whereas in cell-free culture, an average of 2.5 × 10 7 spirochetes/mL were counted. When cultivated with A. cajennense cells, the final count of spirochetes was on average 1.7 × 10 7 spirochetes/mL, while spirochetes cultured under cell-free conditions replicated on average of 2.
We aimed to detect DNA of Borrelia burgdorferi in whole blood and serum samples of patients with clinical symptoms and epidemiology compatible with Brazilian Lyme-like disease. Four patients with positive epidemiological histories were recruited for the study. Blood samples were collected, screened by serologic testing by ELISA and Western blotting and molecular identification of B. burgdorferi by amplifying a fragment of the conserved gene that synthesizes the hook flagellar flgE. The results showed positive serology and for the first time, the presence of B. burgdorferi sensu lato in humans in the Midwest region of Brazil. The resulting sequences were similar to GenBank corresponding sequences of B. burgdorferi flgE gene. By neighbor-joining the phylogenetic analysis, the flgE sequence of the Brazilian strain clustered in a monophyletic group with the sequence of B. burgdorferi sensu lato under 100% bootstrap support. This study opens up promising perspectives and reinforces the need for additional studies to determine the epidemiological characteristics of the disease, as well as the impact of the prevalence of Brazilian borreliosis in Mato Grosso do Sul State, Brazil.
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