Banca de DEFESA: JACKSON ALVES DA SILVA QUEIROZ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JACKSON ALVES DA SILVA QUEIROZ
DATA : 17/02/2022
HORA: 08:30
LOCAL: Sala Virtual Remota
TÍTULO:

Desenvolvimento de ensaio one step multiplex RT-qPCR quantitativo para monitoramento de carga viral de SARS-CoV-2 em indivíduos infectados com diferentes variantes

PALAVRAS-CHAVES:

SARS-CoV-2; Quantitative RT-qPCR; Viral persistence; Variants; Mutations.

PÁGINAS: 82
GRANDE ÁREA: Ciências Biológicas
ÁREA: Biologia Geral
RESUMO:

COVID-19 has caused public health challenges due to the emergence of new variants, reinfections, and lack of treatment. The gold standard for diagnosing SARS-CoV-2 is qualitative RT-qPCR; however, the role of viral load quantification has not yet been fully investigated. Furthermore, studies correlating the persistence of SARS-CoV-2 and disease progression remain scarce. Thus, we aimed to develop a quantitative RT-qPCR assay for monitoring SARS-CoV-2 viral load in individuals infected with different variants. The assay standardization involved the absolute quantification method from a recombinant plasmid with the N gene of SARS-CoV-2 in biological matrix to construct a standard curve. Genome sequencing was performed using the study samples with Ct values <30 to determine SARS-CoV-2 variants and mutations. 244 samples with prior qualitative diagnosis were used for assay validation. The results demonstrated the possibility of quantifying up to 2.5 copies/reaction and analysis of the 244 patients with known results showed 100% agreement with an Anvisa registered qualitative assay. In addition, we performed viral load monitoring in 47 individuals on a weekly basis. During this evaluation, persistent viral load was detected for up to 24 days in 3 individuals. The Gamma variant was detected in 40.4% of the individuals, and this group had a higher initial viral load compared to the non-Gamma individuals. We selected 10 individuals hospitalized with severe COVID-19 and the result showed the presence of the Gamma variant in 70% of the cases, and in this same population a death rate of 50% was observed. With sequencing results it was possible to detect the variants B.1.1.33 (1/20), Gamma (13/20), P.1.4 (1/20) and Zeta (3/20), besides 57 mutations found in different viral genes, among these, the ORF9b:Q77E mutation not yet described in the databases. Conclusion: The results demonstrate the practical application of a highly sensitive quantitative test for SARS-CoV-2, which can be a useful tool in infection monitoring and highlights the importance of genomic surveillance to identify and monitor variants and mutations that may implicate in changing the viral load profile of SARS-CoV-2.

MEMBROS DA BANCA:
Presidente - 643.265.191-34 - DEUSILENE SOUZA VIEIRA - UNIR
Externo à Instituição - FELIPE GOMES NAVECA - FIOCRUZ
Interno - 739.335.462-49 - SORAYA DOS SANTOS PEREIRA - UNIR