Banca de QUALIFICAÇÃO: LUCAS AGUIAR ROSA MACHADO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : LUCAS AGUIAR ROSA MACHADO
DATE: 01/12/2025
TIME: 09:00
LOCAL: Departamento de Parasitologia Animal
TITLE:

Validation and Implementation at the National Level of an Online Platform for Molecular Identification of Brazilian Ticks.

KEY WORDS:

Keywords: PCR-RFLP, Ixodida, Rickettsia.

PAGES: 67
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

Ticks and rickettsiae are organisms of interest in human and animal health due to the diseases they transmit or cause. Brazil has a rich diversity of species of these organisms, and new species continue to be found to this day. Despite this, due to the high cost of sequencing, recent studies fail to identify all their ticks at the species level, leaving the larvae at the genus level. Furthermore, rickettsial co-infection is not a well-understood phenomenon and is difficult to observe with universal primers. PCR-RFLP-based methods for lower-cost identification of ticks and rickettsiae were previously developed by LBioMol. This study aimed to facilitate the use of these methods; generate new identification profiles for ticks and confirm the quality of the sequences used to create and update the method for ticks. To this end, a survey of 16S rDNA sequences of Brazilian Ixodida was carried out, and in the case of Amblyomma spp. sequences, origin and size data were annotated and compared. All collected sequences were aligned at 100% similarity to create haplotypes, and for Amblyomma spp., variation tables were created for comparison. The haplotypes were aligned at 97% similarity and used to create consensus sequences, which in turn were used in phylogeny. Digestion profiles were generated for the Ixodida haplotypes through in silico digestion. While for rickettsiae, the profiles generated by LBioMol were inserted into an online tool created with Wix. In total, 48.31% of the surveyed sequences were collected in Brazil, while the remaining sequences were collected in 17 different countries or did not have their place of origin reported. 29 deposited sequences were observed with the wrong species, and the correct species was identified through BLAST. Two phylogenetic trees were constructed, generating a total of 176 digestion profiles for 74 species of ticks found in national territory, and a dichotomous key was created to facilitate the identification of these species. The online tool created for Rickettsia spp. supports the identification of species and strains found in national territory using different molecular targets.

COMMITTEE MEMBERS:
Interno - 1354903 - DOUGLAS MCINTOSH
Interno - 3701492 - HUARRISSON AZEVEDO SANTOS
Interna - 3103478 - MARISTELA PECKLE PEIXOTO
Externa ao Programa - 1815763 - IRENE DA SILVA COELHO - UFRRJ