Banca de DEFESA: JONATHAN DAVID RIBAS CHAGAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JONATHAN DAVID RIBAS CHAGAS
DATE: 26/09/2023
TIME: 13:30
LOCAL: Videoconferência
TITLE:

Epidemiological, hematological aspects and genetic diversity of Ehrlichia canis in thrombocytopenic dogs from two mesoregions of the state of Rio de Janeiro

KEY WORDS:

molecular characterization, Ehrlichia canis, epidemiology, hematology

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

Ehrlichia canis is a gram-negative, obligatory  intracellular bacterium, responsible for Canine Monocytic Ehrlichiosis (CME), which is transmitted by Rhipicephalus sanguineus sensu lato. Its distribution is favored by regions with a temperate, subtropical and tropical climate, being described in all regions of Brazil, with prevalences ranging from 4.8 to 65% in dogs from urban or rural environments. Studies with E. canis have identified immunoreactive proteins that present species-specific antigens and are related to the parasite-host interaction, providing information about the genetic diversity of the pathogen. In this context, the study aimed to analyze the epidemiological, hematological aspects and genetic diversity of E. canis using the p28 and TRP36 genes in whole blood samples from naturally infected thrombocytopenic dogs from two mesoregions of the state of Rio de Janeiro. In the study, 404 whole blood samples from thrombocytopenic dogs, from the Metropolitan and Southern Fluminense mesoregions, in the state of Rio de Janeiro, were used to perform a blood count with hemoparasite screening and molecular analysis using the dsb, p28 and TRP36 genes. Furthermore, the variables sex, breed and age of the dogs were used to evaluate the correlation with positivity for E. canis. Of the samples analyzed, 21.04% (85/404) amplified for the dsb gene of Ehrlichia spp. and for the E. canis p28 gene. Of these, there was amplification of 34.11% (29/85) for the TRP36 gene. For sequencing and analysis of genetic diversity, 23 samples were used in the p28 gene and 17 samples in the TRP36 gene. The p28 sequences demonstrated similarity with strains from the United States of America (USA) and the Jaboticabal -SP strain (Brazil). Analyzing the sequences obtained with the TRP36 coding gene, it was observed that the study sequences demonstrated a TEDSVSAPA and ASVVPEAE amino acid repeat pattern. Anemia and plasma protein concentration were the significant hematological findings. Only the age variable, dogs aged up to 12 months, was associated with positivity for E. canis. The results demonstrated that there are two genotypes of E. canis circulating in the state of Rio de Janeiro and that young dogs are the most infected by the hemoparasite.

COMMITTEE MEMBERS:
Presidente - 3247559 - BRUNA DE AZEVEDO BAETA
Interno - 3701492 - HUARRISSON AZEVEDO SANTOS
Interna - 3103478 - MARISTELA PECKLE PEIXOTO
Externa à Instituição - NATHALIE COSTA DA CUNHA - UFF
Externo à Instituição - RENATA FERNANDES FEREIRA DE MORAES - UV