Titre : | EVOLUTIONARY DYNAMICS OF SARS-COV-2 DELTA AND OMICRON VARIANTS IN MOROCCO: WHOLE GENOME SEQUENCING AND GENOMIC ANALYSIS | Type de document : | thèse | Auteurs : | EL MAZOURI SAFAE, Auteur | Année de publication : | 2024 | Langues : | Anglais (eng) | Mots-clés : | SARS-CoV-2 Variants Genomic Surveillance Evolutionary Dynamics Spike
Protein Pandemic Variants du SARS-CoV-2 Surveillance Génomique Dynamique Évolutive Protéine Spike Pandémie سالالت فيروس سارس-كوف2- مراقبة جينية ديناميات تطورية بروتين سبايك جائحة | Résumé : | The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, has posed
unprecedented global health challenges. This thesis provides a comprehensive monitoring of
the genetic characteristics and evolutionary patterns of the Delta and Omicron variants of
SARS-CoV-2 in Morocco. Employing the Ion Torrent S5 Prime for Next Generation
Sequencing, we have sequenced 415 of SARS-CoV-2 genomes, submitted to the GISAID
database, from March 2020 to November 2022. The dataset specifically emphasizes the analysis
of 164 Delta and 937 Omicron genomes originating from Morocco. For the Delta variant, our
research detects at least four separate introductions into Morocco, linked to international
sources. The Delta sub-lineage AY.33 was found to be dominant in the region. This study also
uncovers three mutations in the Spike protein's N-terminal domain (NTD) specific to Moroccan
AY.33 isolates: T29A, T250I, and T299I. These mutations may affect the Spike protein's
function and have implications for the variant's behavior. In studying the Omicron variant, our
analysis identifies a distinctive genetic diversity in Moroccan SARS-CoV-2 genomes,
diverging from other global strains. This variant was introduced into Morocco through multiple
sources, as evidenced by the genomic data. Among the Omicron lineages, certain clades
demonstrated higher transmissibility, with clade 22E becoming globally dominant. Notably,
mutations in the Receptor-Binding Domain (RBD) of the Spike protein, such as K444T and
N460K, were identified. These mutations potentially enhance the variant's ability to evade
immunity conferred by vaccines. The findings from this research emphasize the importance of
continuous genomic surveillance to understand local and global genomic dynamics of SARS-
CoV-2. This approach is vital for effective pandemic response and for preparing public health
measures to mitigate the spread of current and future variants. This thesis not only enhances
our understanding of the COVID-19 pandemic in Morocco but also offers valuable insights for
international public health considerations. | Numéro (Thèse ou Mémoire) : | D0052024 | Président : | Abdelilah LARAQUI | Directeur : | Mouna OUADGHIRI | Juge : | Abdenbi EL KARKOURI | Juge : | Hicham EL ANNAZ | Juge : | Yassir BOUSLIMAN ; Abdelhakim BOUYAHYA ; Tarik AANNIZ |
EVOLUTIONARY DYNAMICS OF SARS-COV-2 DELTA AND OMICRON VARIANTS IN MOROCCO: WHOLE GENOME SEQUENCING AND GENOMIC ANALYSIS [thèse] / EL MAZOURI SAFAE, Auteur . - 2024. Langues : Anglais ( eng) Mots-clés : | SARS-CoV-2 Variants Genomic Surveillance Evolutionary Dynamics Spike
Protein Pandemic Variants du SARS-CoV-2 Surveillance Génomique Dynamique Évolutive Protéine Spike Pandémie سالالت فيروس سارس-كوف2- مراقبة جينية ديناميات تطورية بروتين سبايك جائحة | Résumé : | The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, has posed
unprecedented global health challenges. This thesis provides a comprehensive monitoring of
the genetic characteristics and evolutionary patterns of the Delta and Omicron variants of
SARS-CoV-2 in Morocco. Employing the Ion Torrent S5 Prime for Next Generation
Sequencing, we have sequenced 415 of SARS-CoV-2 genomes, submitted to the GISAID
database, from March 2020 to November 2022. The dataset specifically emphasizes the analysis
of 164 Delta and 937 Omicron genomes originating from Morocco. For the Delta variant, our
research detects at least four separate introductions into Morocco, linked to international
sources. The Delta sub-lineage AY.33 was found to be dominant in the region. This study also
uncovers three mutations in the Spike protein's N-terminal domain (NTD) specific to Moroccan
AY.33 isolates: T29A, T250I, and T299I. These mutations may affect the Spike protein's
function and have implications for the variant's behavior. In studying the Omicron variant, our
analysis identifies a distinctive genetic diversity in Moroccan SARS-CoV-2 genomes,
diverging from other global strains. This variant was introduced into Morocco through multiple
sources, as evidenced by the genomic data. Among the Omicron lineages, certain clades
demonstrated higher transmissibility, with clade 22E becoming globally dominant. Notably,
mutations in the Receptor-Binding Domain (RBD) of the Spike protein, such as K444T and
N460K, were identified. These mutations potentially enhance the variant's ability to evade
immunity conferred by vaccines. The findings from this research emphasize the importance of
continuous genomic surveillance to understand local and global genomic dynamics of SARS-
CoV-2. This approach is vital for effective pandemic response and for preparing public health
measures to mitigate the spread of current and future variants. This thesis not only enhances
our understanding of the COVID-19 pandemic in Morocco but also offers valuable insights for
international public health considerations. | Numéro (Thèse ou Mémoire) : | D0052024 | Président : | Abdelilah LARAQUI | Directeur : | Mouna OUADGHIRI | Juge : | Abdenbi EL KARKOURI | Juge : | Hicham EL ANNAZ | Juge : | Yassir BOUSLIMAN ; Abdelhakim BOUYAHYA ; Tarik AANNIZ |
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