Prevalence of GII.4 and GII.17 genotypes in the population of the state of Maranhão, Amazon region in Brazil and whole genome sequencing of GII.17 genotypes.

Yan Pimenta, Oswaldo Cruz Institute

Yan Cardoso Pimenta1, 2*, Fabiano Vieira da Silva3, Marcia Terezinha Baroni de Moraes 1, 2* 1Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute, Oswaldo Cruz Fundation, Fiocruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil; yancpimenta@gmail.com( Y.C.P.); baroni@ioc.fiocruz.br (M.T.B.M.). 2. Post-Graduate Program in Tropical Medicine, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Fiocruz, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil; yancpimenta@gmail.com( Y.C.P.); baroni@ioc.fiocruz.br (M.T.B.M.). 3. Central Public Health Laboratory of Maranhão-IOC (LACEN-MA), Oswaldo Cruz Institute, Rua Osvaldo Cruz, S/N, Centro, São Luís, MA, 65015-280, Brazil; fabianoimh@gmail.com.

Molecular Epidemiology & Evolution

Norovirus is a leading cause of acute gastroenteritis (AGE) worldwide, causing high morbidity and affecting all ages, especially children under 5 and the elderly. These viruses are classified into 10 genogroups and 49 genotypes based on the major capsid protein (VP1). The GII.4 genotype is the most prevalent and linked to outbreaks, but recent molecular studies show increasing prevalence of the GII.17 genotype. Whole genome analysis is an important tool to understand viral variability in population. Sixty samples norovirus GII positives by real-time PCR (cycle threshold [Ct] under 37) were submitted to PCR and nucleotide sequencing using primers for the VP1 and RNA-dependent RNA polymerase (RdRp) regions. Noroviruses genotyped as GII.17 were subjected to whole genome amplification using the protocol described by Ji, L et al. 2018, with significant modifications. Twenty GII norovirus (33%, 20/60) were genotyped as GII.4 [P16] (n= 15) and GII.17 [P17] (n= 5). Whole genome of GII.17[P17] was assessed through the amplification of 3 large PCR fragments, which were subjected to Sanger sequencing. A comparative analysis of the complete nucleotide sequence of norovirus GII.17 from this study is being carried out to provide information on the variability and probable entry routes of this genotype into the study population. In this study, we highlight the prevalence of GII.4 and GII.17 infecting the population of the state of Maranhão, Amazon region in Brazil, and present a simple protocol where three PCR fragments are obtained and subjected to Sanger sequencing to evaluate the whole genome of GII.17 genotypes.