ABSTRACT

Information regarding the genomic variability, and susceptibility profile to antiviral drug resistance are scarce for influenza A/H1N1pdm09 strains circulating in Morocco. The aims of this study are to survey genetic changes in the hemagglutinin (HA) and neuraminidase (NA)genes and to phenotypically assess the antiviral drug resistance (AVR) to neuraminidase inhibitors (NAIs) drugs- related mutations. During the 2015-2016 flu season, 1189 nasopharyngeal swabs samples were collected from influenza- like illness (ILI) and severe acute respiratory illness (SARI) patients in eight sentinel sites distributed throughout the country. Reactive samples by rRT-PCR were inoculated on MDCK cell-line for virus isolation. Sequencing and phylogenetic analysis of HA and NA genes were performed to evaluate the genetic diversity of Moroccan A/H1N1pdm09 strains. AVR screening against two NAIs (oseltamivir and zanamivir) was performed on MDCK-propagated viruses using the functional neuraminidase inhibition assay. Among those 1,189 specimens, 185 were A/H1N1pdm09, 59 A/H3N2, and 30 influenza B. Ninety-six of the 185 A/H1N1pdm09 propagated strains had a HA titer of at least 1:16 and were subjected to NAIs assay. Phylogenetic analysis of HA and NA genes revealed that Moroccan A/H1N1pdm09 isolates clustered with the predominate genetic group 6B.1. Several amino acid changes in the antigenic site were identified: S203T, S189T, K163Q, and S162N (N1 numbering), as well as a unique S185T in the receptor-binding domain. The NA assay showed no increased resistance (normal inhibition) against both NAI drugs in all tested isolates. This study confirms that A/H1N1pdm09 circulating strains in Morocco have undergone genetic variability and dynamic evolution. Surveillance of viral genetic evolution is important for disease management and appropriate public health interventions during influenza outbreaks Keywords: Influenza, Hemagglutinin; Neuraminidase; Neurminidase Inhibitors
Publication date: 01/10/2023

https://ijbpas.com/pdf/2023/March/MS_IJBPAS_2023_7518.pdf

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https://doi.org/10.31032/IJBPAS/2023/12.10.7518