Banca de QUALIFICAÇÃO: DAVI GUIMARAES DE ALMEIDA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : DAVI GUIMARAES DE ALMEIDA
DATE: 25/08/2025
TIME: 13:30
LOCAL: Videoconferência
TITLE:

Study of Rickettsia spp. and Borrelia spp. in free-living and wild animal ticks

KEY WORDS:

ticks, Rickettsia, Borrelia, Brazilian biomes, zoonoses, One Health.

PAGES: 47
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

This study investigated the occurrence and molecular characterization of Rickettsia spp. and Borrelia spp. in free-living ticks and those collected from wild animals in the Amazon, Cerrado, and Atlantic Forest biomes. The research is grounded on the relevance of these vectors in the transmission of emerging zoonoses and the need to understand their ecology in different Brazilian environments. A total of 423 ticks were morphologically identified and screened by conventional PCR (gltA for Rickettsia spp.) and Nested-PCR (flaB for Borrelia spp.), followed by genetic sequencing. Of all samples, 39 (9.2%) tested positive for Rickettsia spp., exclusively from the Amazon (48.7%) and Atlantic Forest (51.3%). Positive species included Amblyomma cajennense sensu lato (43.6%), A. sculptum (17.9%), A. dubitatum (17.9%), A. ovale (7.7%), as well as occasional findings of A. geayi, A. parkeri, and Ixodes loricatus. Notably, this represents the first report of Rickettsia spp. detection in A. geayi parasitizing sloths (Bradypus variegatus) in the Amazon region. No Borrelia spp. DNA was detected. The results highlight the role of Amblyomma ticks as the main vectors of rickettsiae in Brazil, particularly in association with wild hosts such as capybaras and sloths, which are relevant to the maintenance of enzootic cycles. In conclusion, molecular surveillance of these pathogens across different biomes is essential to assess zoonotic risks, support One Health strategies, and advance the understanding of the epidemiology of rickettsioses in the country.

COMMITTEE MEMBERS:
Presidente - 3247559 - BRUNA DE AZEVEDO BAETA
Interna - 3103478 - MARISTELA PECKLE PEIXOTO
Externa à Instituição - IZABELA MESQUITA ARAÚJO - UFRRJ
Externo à Instituição - PAULO CÉSAR MAGALHÃES MATOS - IFAP
Externo à Instituição - RODRIGO GREDILHA DUARTE - UNIRIO