First record of Borrelia burgdorferi B31 strain in Dermacentor nitens ticks in the northern region of Parana (Brazil)

The aim of this study was to investigate the presence of DNA of Borrelia burgdorferi sensu lato (s.l.) in ticks that feed on horses used for animal traction in rural Jataizinho, Parana, Brazil. Between February and June 2008, a total of 224 ticks was collected of which 75% were identified as Dermacentor nitens and 25% as Amblyomma cajenense. To amplify B. burgdorferi s.l. DNA, the intergenic space region (ISR) between the 5S (rrf) 23S (rrl) rRNA genes was used as targets for nested-PCR. Two ticks of the D. nitens species were positive for B. burgdorferi s.l. Both species showed a fragment of 184 bp, but the sequencing revealed 99.9% homology with the B. burgdorferi sensu stricto (s.s.) strain B31. These results showed, for the first time, the presence of spirochete DNA infecting ticks that parasitize horses used for animal traction, in the rural municipality mentioned. In conclusion, this study opens up promising prospects for determining the infection rate of B. burgdorferi s.s. genospecies or other species in the equine population, as well as the impact of the infection rate on Lyme disease in the state of Parana.

Doença de lyme-símile brasileira ou síndrome baggioyoshinari: zoonose exótica e emergente transmitida por carrapatos: [revisão] / Brazilian lyme-like disease or baggio-yoshinari syndrome: exotic and emerging brazilian tick-borne zoonosis: [review]

A Doença de Lyme (DL) é uma zoonose frequente no hemisfério Norte e considerada uma enfermidade infecciosa causada por espiroquetas do complexo Borrelia burgdorferi sensu lato e transmitida pela picada de carrapatos do grupo Ixodes ricinus. Os primeiros casos semelhantes à DL no Brasil foram descobertos, em 1992, em irmãos que após serem picados por carrapatos desenvolveram eritema migratório, sintomas gripais e artrite. Criteriosa análise da casuística brasileira, mostrou que os aspectos epidemiológicos, clínicos e laboratoriais no país, divergiam bastante dos exibidos pelos pacientes com DL nos Estados Unidos da América e Eurásia. Não foram encontrados carrapatos do complexo Ixodes ricinus hematófago ao homem nas áreas de risco; a enfermidade no país é recorrente; a Borrelia burgdorferi jamais foi isolada no Brasil e os ensaios sorológicos específicos exibem positividade baixa e oscilante. Além disso, o exame do sangue periférico dos pacientes quando analisados à microscopia eletrônica exibe estruturas sugestivas de Mycoplasma spp, Chlamydia spp e bacteroides. Na verdade, estas estruturas podem representar as formas latentes das espiroquetas (forma L ou bactérias desprovidas de parede), adaptadas a sobreviver em condições inóspitas em hospedeiros vertebrados e invertebrados. Assim, a zoonose presente no país recebeu a denominação de Síndrome Baggio-Yoshinari e definida como: "Enfermidade infecciosa nova e emergente brasileira, transmitida por carrapatos não pertencentes ao complexo Ixodes ricinus, causada por espiroquetas na sua morfologia atípica e latente, que origina manifestações clínicas semelhantes às observadas na DL, exceto pela ocorrência de recidivas clínicas e desordens autoimunes".

Lyme disease (LD) is a frequent zoonosis found in the Northern Hemisphere and is considered an infectious disease caused by spirochetes belonging sensu lato to the Borrelia burgdorferi complex transmitted by ticks of the Ixodes ricinus group. In 1992, first cases similar to LD were described in Brazil, when brothers, after a tick bite episode developed symptoms , as erythema migrans, general flu-like symptoms and arthritis. Careful analysis of Brazilian LD-like illness casuistry showed that epidemiological, clinical and laboratorial features in the country were very different from those exhibited by North American and Eurasian LD patients. Human blood-suckers Ixodes ricinus complex ticks were absent at risk areas; the disease is recurrent in the country; Borrelia burgdorferi was never isolated in Brazil and specific serologic tests have shown little positivity with inconsistent results. Furthermore, peripheral blood analysis of patients on electron microscopy exhibited structures resembling Mycoplasma spp, Chlamydia spp and spirochete-like microorganisms. In fact, they were assumed to be latent forms of spirochetes (L form or cell wall deficient bacteria) adapted to survive at inhospitable conditions in vertebrate and invertebrate hosts. For these reasons, the Brazilian zoonosis was named Baggio-Yoshinari Syndrome (BYS) and defined as: "Exotic and emerging Brazilian infectious disease, transmitted by ticks not belonging to the Ixodes ricinus complex, caused by latent spirochetes with atypical morphology, which originates LD-like symptoms, except for occurrence of relapsing episodes and auto-immune disorders".