Banca de DEFESA: ANA LEE APARECIDA FRANCISCO
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : ANA LEE APARECIDA FRANCISCO
DATA : 02/06/2021
HORA: 14:00
LOCAL: por participação remota
TÍTULO:
In vitro characterization of samples of Rabies Virus isolated from Cerdocyon thous and Canis lupus familiaris
PÁGINAS: 60
GRANDE ÁREA: Ciências Biológicas
ÁREA: Microbiologia
RESUMO:
Rabies has worldwide distribution and can be maintained in nature by different epidemiological cycles that eventually interrelate. In the urban cycle, the main reservoir is the domestic dog, Canis lupus familiaris and in the terrestrial wild cycle one of the main reservoirs in Brazil is the wild canid, Cerdocyon thous.
These epidemiological cycles has more importance in North and Northeast regions of country. It is currently known that each of these reservoirs is responsible for maintaining a genetic lineage characteristic of rabies virus (RABV). Due to the epidemiological importance that these reservoirs have, analyzing the in vitro behavior of the genetic strains of RABV characteristic of these species is fundamental for a better understanding of this virus. The present study aimed to analyze the in vitro behavior of rabies genetic strains characteristic of wild and domestic canids. Two RABV samples with genetic strain characteristic of Cerdocyon thous (IP4871/11 and IP3208/11), two samples with genetic strain of Canis lupus familiaris (IP3629/11 and IP1972/16) and the standard sample of RABV Pasteur Virus (PV) were used. Initially, IP4871/11, IP3208/11 and PV samples were adapted into HEK-293T cells and submitted to replication kinetic scans. After the adaptation process the samples were submitted to virus titration and the titres were expressed as log10 tissue culture infectious doses per 50 μl (TCID50/50 μl). The work titres obtained respectively were 104.5 TCID 50, 105.75 TCID 50 and 104.0 TCID50. In the viral growth curve, the HEK-293T cells were inoculated in triplicate with 100 DICC50 of virus and then submitted to adsorption for a period of two hours at 37ºC before inoculum removal, and the extracellular virus inactivated with sodium citrate (pH 3.0). The monolayers were then washed with fresh medium and incubated at different intervals (1, 12, 24, 36, 48, 60, 72, 84 and 96 hours pos inoculation-p.i.). After the incubation period, the supernatants were collected and submitted to virus titration. The statistical analysis was performed comparing the average results of the titres for each sample. For RABV samples with a genetic lineage characteristic of Cerdocyon thous, it was possible to identify viral presence 24 hours p.i., with increased viral load up to 84 hours p.i. and decreased viral load with 96 hours p.i. For PV, it was possible to identify viral title 12 hours p.i., with increased viral load up to 72 hours p.i. and from 84 hours p.i. When analyzing these data, it was observed that the samples belonging to the genetic lineage characteristic of Cerdocyon thous (IP4871/11 and IP3208/11) showed later viral growth, demonstrating different in vitro behavior when compared with PV. The study predics the comparison of these results with samples of RABV with genetic lineage characteristic of Canis lupus familiaris. These results are important for a better understanding of the maintenance of RABV in nature, its virologicals characteristics, as well as for the development of vaccines and specific serological tests against the genetic lineage of RABV characteristic of Cerdocyon thous and thus contribute to future strategies aimed at the control of wild rabies in the country.
MEMBROS DA BANCA:
Presidente - Interno ao Programa - 927.634.300-82 - HELENA BEATRIZ DE CARVALHO RUTHNER BATISTA - UFRGS
Membro Titular - Examinador(a) Interno ao Programa - 2605490 - SERGIO DAISHI SASAKI
Membro Titular - Examinador(a) Externo à Instituição - JULIANA GALERA CASTILHO KAWAI - IP
Membro Suplente - Examinador(a) Externo à Instituição - WILLIAN DE OLIVEIRA FAHL
Membro Suplente - Examinador(a) Externo à Instituição - KARIN CORRÊA SCHEFFER FERREIRA