Banca de DEFESA: DÉBORA MARTINS DOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DÉBORA MARTINS DOS SANTOS
DATE: 30/08/2021
TIME: 09:00
LOCAL: A defesa será realizada utilizando a plataforma Google Meet
TITLE:

Epidemiological and molecular aspects of Ehrlichia canis in dogs living in cities with different altitude in the state of Rio de Janeiro

KEY WORDS:

Ehrlichia canis, epidemiology, altitude, phylogenetic analysis

PAGES: 72
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Parasitárias de Animais
SUMMARY:

Canine Monocytic Ehrlichiosis is one of the most frequently diagnosed diseases in the dogs routine veterinary care. The goal of this study was to analyze the epidemiology and the genetic variability of the 16S rRNA sequence of Ehrlichia canis in blood samples from dogs living in different counties of the Rio de Janeiro State with diverse altitude ranges during the period of one year. A total of 456 blood samples were collected to be epidemiology and molecularly analyzed. Total DNA was extracted from the blood, using a DNA Extraction Kit (DNeasy Blood & Tissue kit QIAGEN). DNA samples were subjected to qPCR aiming at the 16S rRNA sequence, following protocol as previously described in the literature. Afterwards, two conventional PCR reactions were run, as was also described in the literature, in the intent of characterizing the 16S Gene in positive samples. In the logistical regression model an association between E. canis positive dogs and higher altitudes (p<0.002) was observed. Dogs residing in low altitude counties have 2.18 times more chance of being infected by E. canis when compared to dogs residing in high altitude counties. The variables access to urban environment, infestation by Rhipicephalus sanguíneus s.l ticks and pure breed dogs were also associated with the presence of E. canis in the blood canine subjects. The environmental variables such as high altitude, access to urban environment, infestation by Rhipicephalus sanguíneus s.l ticks and pure breed dogs explain 73% of the occurrence of E. canis in dogs in the areas studied. These results show that the altitude has positive influence over causal factors and frequency of infection by E. canis in dogs of the studied area as well as the dogs intrinsic characteristics. In the phylogenetic analysis, all sequences obtained in this study were grouped in the E. canis clade.  This demonstrates that the 16S rRNA sequence is an excellent phylogenetic marker for taxonomic classifications. However, due to its highly conservative characteristics it’s not as good for assessing genetic diversity. The 16S rRNA sequences obtained from samples collected in the Teresopolis municipality showed more genetic variations when compared to those collected in Paracambi municipality. It is possible that such diversity be a consequence of environmental conditions that need further elucidation.

BANKING MEMBERS:
Presidente - 3701492 - HUARRISSON AZEVEDO SANTOS
Externa ao Programa - 3247559 - BRUNA DE AZEVEDO BAETA
Externa ao Programa - 3103478 - MARISTELA PECKLE PEIXOTO
Externa ao Programa - 1125765 - SANDRA MARIA GOMES THOME
Externo à Instituição - DANIEL DA SILVA GUEDES JUNIOR - FIOCRUZ
Externa à Instituição - ALINE MOREIRA DE SOUZA - UFF
Externa à Instituição - NATHALIE COSTA DA CUNHA - UFF