Molecular epidemiology of AY.28 and AY.104 delta sub-lineages in Sri Lanka

<p><strong>Background:</strong> The worst SARS-CoV-2 outbreak in Sri Lanka was due to the two Sri Lankan delta sub-lineages AY.28 and AY.104. We proceeded to further characterize the mutations and clinical disease severity of these two sub-lineages.</p> <p><strong&g...

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Main Authors: Ranasinghe, D, Jayathilaka, DJ, Jeewandara, C, Gunasinghe, D, Ariyaratne, D, Jayadas, TTP, Kuruppu, H, Wijesinghe, A, Bary, FF, Madhusanka, D, Pushpakumara, PD, Guruge, D, Wijayamuni, R, Ogg, GS, Malavige, GN
Format: Journal article
Language:English
Published: Frontiers Media 2022
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author Ranasinghe, D
Jayathilaka, DJ
Jeewandara, C
Gunasinghe, D
Ariyaratne, D
Jayadas, TTP
Kuruppu, H
Wijesinghe, A
Bary, FF
Madhusanka, D
Pushpakumara, PD
Guruge, D
Wijayamuni, R
Ogg, GS
Malavige, GN
author_facet Ranasinghe, D
Jayathilaka, DJ
Jeewandara, C
Gunasinghe, D
Ariyaratne, D
Jayadas, TTP
Kuruppu, H
Wijesinghe, A
Bary, FF
Madhusanka, D
Pushpakumara, PD
Guruge, D
Wijayamuni, R
Ogg, GS
Malavige, GN
author_sort Ranasinghe, D
collection OXFORD
description <p><strong>Background:</strong> The worst SARS-CoV-2 outbreak in Sri Lanka was due to the two Sri Lankan delta sub-lineages AY.28 and AY.104. We proceeded to further characterize the mutations and clinical disease severity of these two sub-lineages.</p> <p><strong>Methods:</strong> 705 delta SARS-CoV-2 genomes sequenced by our laboratory from mid-May to November 2021 using Illumina and Oxford Nanopore were included in the analysis. The clinical disease severity of 440/705 individuals were further analyzed to determine if infection with either AY.28 or AY.104 was associated with more severe disease. Sub-genomic RNA (sg-RNA) expression was analyzed using periscope.</p> <p><strong>Results:</strong> AY.28 was the dominant variant throughout the outbreak, accounting for 67.7% of infections during the peak of the outbreak. AY.28 had three lineage defining mutations in the spike protein: A222V (92.80%), A701S (88.06%), and A1078S (92.04%) and seven in the ORF1a: R24C, K634N, P1640L, A2994V, A3209V, V3718A, and T3750I. AY.104 was characterized by the high prevalence of T95I (90.81%) and T572L (65.01%) mutations in the spike protein and by the absence of P1640L (94.28%) in ORF1a with the presence of A1918V (98.58%) mutation. The mean sgRNA expression levels of ORF6 in AY.28 were significantly higher compared to AY.104 (p < 0.0001) and B.1.617.2 (p < 0.01). Also, ORF3a showed significantly higher sgRNA expression in AY.28 compared to AY.104 (p < 0.0001). There was no difference in the clinical disease severity or duration of hospitalization in individuals infected with these sub lineages.</p> <p><strong>Conclusions:</strong> Therefore, AY.28 and AY.104 appear to have a fitness advantage over the parental delta variant (B.1.617.2), while AY.28 also had a higher expression of sg-RNA compared to other sub-lineages. The clinical implications of these should be further investigated.</p>
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spelling oxford-uuid:959c26bf-59ff-48c9-a19a-b10f8bb3fe0d2023-09-26T15:13:15ZMolecular epidemiology of AY.28 and AY.104 delta sub-lineages in Sri LankaJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:959c26bf-59ff-48c9-a19a-b10f8bb3fe0dEnglishSymplectic ElementsFrontiers Media 2022Ranasinghe, DJayathilaka, DJJeewandara, CGunasinghe, DAriyaratne, DJayadas, TTPKuruppu, HWijesinghe, ABary, FFMadhusanka, DPushpakumara, PDGuruge, DWijayamuni, ROgg, GSMalavige, GN<p><strong>Background:</strong> The worst SARS-CoV-2 outbreak in Sri Lanka was due to the two Sri Lankan delta sub-lineages AY.28 and AY.104. We proceeded to further characterize the mutations and clinical disease severity of these two sub-lineages.</p> <p><strong>Methods:</strong> 705 delta SARS-CoV-2 genomes sequenced by our laboratory from mid-May to November 2021 using Illumina and Oxford Nanopore were included in the analysis. The clinical disease severity of 440/705 individuals were further analyzed to determine if infection with either AY.28 or AY.104 was associated with more severe disease. Sub-genomic RNA (sg-RNA) expression was analyzed using periscope.</p> <p><strong>Results:</strong> AY.28 was the dominant variant throughout the outbreak, accounting for 67.7% of infections during the peak of the outbreak. AY.28 had three lineage defining mutations in the spike protein: A222V (92.80%), A701S (88.06%), and A1078S (92.04%) and seven in the ORF1a: R24C, K634N, P1640L, A2994V, A3209V, V3718A, and T3750I. AY.104 was characterized by the high prevalence of T95I (90.81%) and T572L (65.01%) mutations in the spike protein and by the absence of P1640L (94.28%) in ORF1a with the presence of A1918V (98.58%) mutation. The mean sgRNA expression levels of ORF6 in AY.28 were significantly higher compared to AY.104 (p < 0.0001) and B.1.617.2 (p < 0.01). Also, ORF3a showed significantly higher sgRNA expression in AY.28 compared to AY.104 (p < 0.0001). There was no difference in the clinical disease severity or duration of hospitalization in individuals infected with these sub lineages.</p> <p><strong>Conclusions:</strong> Therefore, AY.28 and AY.104 appear to have a fitness advantage over the parental delta variant (B.1.617.2), while AY.28 also had a higher expression of sg-RNA compared to other sub-lineages. The clinical implications of these should be further investigated.</p>
spellingShingle Ranasinghe, D
Jayathilaka, DJ
Jeewandara, C
Gunasinghe, D
Ariyaratne, D
Jayadas, TTP
Kuruppu, H
Wijesinghe, A
Bary, FF
Madhusanka, D
Pushpakumara, PD
Guruge, D
Wijayamuni, R
Ogg, GS
Malavige, GN
Molecular epidemiology of AY.28 and AY.104 delta sub-lineages in Sri Lanka
title Molecular epidemiology of AY.28 and AY.104 delta sub-lineages in Sri Lanka
title_full Molecular epidemiology of AY.28 and AY.104 delta sub-lineages in Sri Lanka
title_fullStr Molecular epidemiology of AY.28 and AY.104 delta sub-lineages in Sri Lanka
title_full_unstemmed Molecular epidemiology of AY.28 and AY.104 delta sub-lineages in Sri Lanka
title_short Molecular epidemiology of AY.28 and AY.104 delta sub-lineages in Sri Lanka
title_sort molecular epidemiology of ay 28 and ay 104 delta sub lineages in sri lanka
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