Banca de DEFESA: LAIS DA SILVA DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LAIS DA SILVA DE OLIVEIRA
DATE: 17/12/2025
TIME: 09:00
LOCAL: Plataforma Zoom - ONLINE
TITLE:

Cytological and Molecular Evaluation of Protozoa of the Phylum Apicomplexa in Domestic Dogs and Cats in the State of Rio de Janeiro

KEY WORDS:

Keywords: Babesiidae, Hepatozoidae, Molecular Detection.

PAGES: 60
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

Dogs and cats play a fundamental role in today’s society, being considered family members and important companions to humans. These animals can harbor a wide variety of vector-borne agents, among which blood protozoa known as hematozoa, belonging to the genera Babesia, Theileria, Hepatozoon, and Rangelia, stand out. These parasites are part of the phy-lum Apicomplexa, which includes organisms of great veterinary and, in some cases, zoonotic relevance.This study aimed to analyze blood samples and blood smear slides from 338 ani-mals, including dogs and cats, treated at the Small Animal Veterinary Hospital of the Federal Rural University of Rio de Janeiro. The samples were sent to the Veterinary Clinical Patholo-gy Laboratory (LABVET) for hematological and cytological processing and then to the Hemoparasites and Vectors Laboratory (LHV), where DNA extraction, and cytological and molecular analyses were performed. The samples were sent to the Laboratory of Hemopara-sites and Vectors (LHV), where DNA extraction and cytological and molecular analyses were performed. The blood smears, stained using the Giemsa method (1:10) and examined under oil-immersion optical microscopy (1000x), showed no forms compatible with hematozoa. In the molecular analysis, qPCR targeting the hsp70 gene of Babesia vogeli detected a positivity rate of 1.8% (n = 6/338) (five dogs and one cat) while nested PCR targeting a fragment of the 18S rRNA gene revealed 0.6% (2/338) of samples positive for piroplasms. For Hepatozoon spp., 1.8% (n = 6/338) of samples were positive by conventional PCR. The sequences ob-tained showed greater than 99% identity with Babesia vogeli and Hepatozoon canis in Gen-Bank, confirming the molecular identification of the agents. Agreement between the methods used for B. vogeli was evaluated using McNemar’s test and the Kappa coefficient; McNemar’s test indicated no significant difference between techniques (p = 0.125), while the Kappa coefficient demonstrated moderate agreement (0.496; p < 0.001), with discordant re-sults restricted to samples positive only by qPCR, reinforcing its higher diagnostic sensitivity. Hematological evaluations showed anemia, thrombocytopenia, hyperproteinemia, and even unremarkable hemograms in animals positive for B. vogeli, whereas animals positive for H. canis exhibited leukocytosis, anemia, hyperproteinemia, and leukopenia. In conclusion, the detection of hematozoa was low, and molecular methods demonstrated greater diagnostic ef-ficiency than cytology, particularly in infections with low parasitemia. Furthermore, qPCR proved to be significantly more sensitive than nested PCR. These findings highlight the im-portance of applying sensitive diagnostic techniques and underscore the need for additional studies to deepen the understanding of these agents in hospital settings, especially in cats, for which many protozoan infections remain poorly studied.

COMMITTEE MEMBERS:
Presidente - 3103478 - MARISTELA PECKLE PEIXOTO
Externa ao Programa - 3324429 - ANDRESA GUIMARAES - UFRRJExterna ao Programa - 1159140 - JULIANA MACEDO RAIMUNDO - UFRRJExterna à Instituição - ALINE MOREIRA DE SOUZA - UFF
Externo à Instituição - DANIEL DA SILVA GUEDES JUNIOR - FIOCRUZ