Banca de DEFESA: KARINA CRISTINA PAES GALDINO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : KARINA CRISTINA PAES GALDINO
DATE: 25/02/2026
TIME: 09:30
LOCAL: Plataforma Google Meet
TITLE:

EXPERIMENTAL INVESTIGATION OF THE VECTOR COMPETENCE OF Theileria equi (PIROPLASMIDA: THEILERIDAE) BY Dermacentor nitens (ACARI: IXODIDAE).

KEY WORDS:

Tick, theileriosis, vector, transmission, infection, epidemiology

PAGES: 53
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

Equine piroplasmosis, caused by Theileria equi, is an endemic disease in Brazil, with significant economic impacts on equine herds due to its high prevalence, despite Rhipicephalus microplus being the main experimentally proven vector. Dermacentor nitens, a tick specific to equines, is frequently associated with infestations in animals positive for T. equi, but its vector competence remains undefined. This study aimed to evaluate the dynamics of T. equi infection in immature stages (larvae and nymphs) and tissues (salivary glands, ovaries, and intestine) of male and female D. nitens, using sensitive molecular tools such as RT-qPCR and nested-PCR. Horses chronically infected with T. equi were infested with larvae of D. nitens free of hemoparasites. Tissues from adult females and males were obtained through dissection, while immature stages were kept in a B.O.D. chamber for ecdysis. Analyses included RNA extraction and detection by RT-qPCR (18S rRNA gene) and nested-PCR (ema-1 gene). A total of 252 samples were analyzed; the prevalence of T. equi by RT-qPCR was 4.2% in females (5/120) and 16.4% in males (11/67), with positive detections also in nymphs and adults, whereas all samples were negative by nested-PCR. The results demonstrate that D. nitens acquires and maintains T. equi infection across stages and in organs, reaching the intestine and salivary glands, but without evidence of infection in ovaries. However, the infection remained discrete, indicating a limitation of D. nitens regarding T. equi infection.

COMMITTEE MEMBERS:
Presidente - 3701492 - HUARRISSON AZEVEDO SANTOS
Interno - ***.781.297-** - CARLOS LUIZ MASSARD - UFRRJ
Externa ao Programa - 1159140 - JULIANA MACEDO RAIMUNDO - UFRRJExterno à Instituição - DANIEL DA SILVA GUEDES JUNIOR - FIOCRUZ
Externa à Instituição - NATHALIE COSTA DA CUNHA - UFF