5 research outputs found
Search for Borrelia sp. in Ticks Collected from Potential Reservoirs in an Urban Forest Reserve in the State of Mato Grosso do Sul, Brazil: a Short Report
A total of 128 ticks of the genus Amblyomma  were recovered
from 5 marsupials ( Didelphis albiventris  ) - with 4
recaptures - and 17 rodents (16 Bolomys lasiurus  and 1 Rattus
norvegicus  ) captured in an urban forest reserve in Campo
Grande, State of Mato Grosso do Sul, Brazil. Of the ticks collected, 95
(78.9%) were in larval form and 22 (21.1%) were nymphs; the only adult
(0.8%) was identified as A. cajennense . Viewed under dark-field
microscopy in the fourth month after seeding, 9 cultures prepared from
spleens and livers of the rodents, blood of the marsupials, and
macerates of Amblyomma sp. nymphs revealed spiral-shaped,
spirochete-like structures resembling those of Borrelia  sp.
Some of them showed little motility, while others were non-motile. No
such structures could be found either in positive Giemsa-stained
culture smears or under electron microscopy. No PCR amplification of
DNA from those cultures could be obtained by employing Leptospira
 sp., B. burgdorferi , and Borrelia sp. primers. These aspects
suggest that the spirochete-like structures found in this study do not
fit into the genera Borrelia or Leptospira, requiring instead to be
isolated for proper identification
The Current State of Knowledge on Baggio–Yoshinari Syndrome (Brazilian Lyme Disease-like Illness): Chronological Presentation of Historical and Scientific Events Observed over the Last 30 Years
Baggio–Yoshinari Syndrome (BYS) is an emerging Brazilian tick-borne infectious disease that clinically mimics Lyme Disease (LD) present in the Northern Hemisphere. LD is caused by spirochetes belonging to the Borrelia burgdorferi sensu lato complex and transmitted by Ixodid ticks of complex Ixodes rticinus. On the contrary, BYS is transmitted by hard Ixodid ticks of the genera Amblyomma, Rhipicephalus and Dermacentor. In 1992, the first cases of BYS were described in patients that developed EM rash, flu-like symptoms and arthritis after tick bite episodes. Since these findings, research in BYS has been developing for more than 30 years and shows that its epidemiological, clinical and laboratorial features are different from LD. Borrelia burgdorferi was never isolated in Brazil. In addition, specific serologic tests have shown little positivity. Furthermore, peripheral blood analysis of patients using electron microscopy exhibited structures resembling spirochete-like microorganisms or the latent forms of spirochetes (L form or cell wall deficient bacteria). For these reasons, Brazilian zoonosis was defined as an exotic and emerging Brazilian infectious disease, transmitted by ticks not belonging to the Ixodes ricinus complex, caused by latent spirochetes belonging to the B. burgdorferi sensu lato complex with atypical morphology. The Brazilian ecosystem, combined with its ticks and reservoir biodiversity, possibly contributed to the origin of this new zoonosis, which emerged as a result of the passage of B. burgdorferi through exotic vectors and reservoirs
Oviposition and eclosion periods of Ixodes didelphidis Fonseca and AragĂŁo, 1951 (Acari: Ixodidae) under laboratory conditions
Oviposition and eclosion periods for Ixodes didelphidis were observed under two temperatures (25ÂșC and 27ÂșC) and 90-95% humidity. Although there was a significant increase in the eclosion period (p<0.05) and a tendency to increase the oviposition period at 25ÂșC, there was neither significant differences in the interval (days), until maximum peak of eclosion nor in the number of emerging larvae during the peak nor the total number of emerged larvae. These temperature values are not critical for embryological development of the species. Because at 27ÂșC and under high humidity the oviposition and eclosion periods are shorter, and the percentage of emerged larvae is higher, we consider this to be the ideal temperature for laboratory studies