Comparative analysis of SARS-CoV-2 variants Alpha (B.1.1.7), Gamma (P.1), Zeta (P.2) and Delta (B.1.617.2) in Vero-E6 cells: ultrastructural characterization of cytopathology and replication kinetics

• DOI: 10.1016/j.bjid.2023.103706
• Publication Date: 2023-12-08T14:31:55Z
• Authors: Debora Ferreira B...; Derick Mendes Ban...; Marcos Alexandre ...; Ana Luisa Teixeir...; Mia Araújo; Ana Beatriz Machado; Luis Fernando Lop...; Valéria Pereira N...; Marilda M. Siqueira; Fernando Couto Motta; Alex Pauvolid-Corrêa; Ortrud Monika Barth
• Keywords: Vero cell

This study compares the effects of virus-cell interactions among SARS-CoV-2 variants concern (VOCs) isolated in Brazil 2021, hypothesizing a correlation between cellular alterations and mortality viral load transmissibility. For this purpose, reference isolates Alpha, Gamma, Zeta, Delta were inoculated into monolayers Vero-E6 cells. Viral RNA was quantified cell supernatants by RT‒PCR, infected cells analyzed Transmission Electron Microscopy (TEM) for qualitative quantitative evaluation changes 24, 48, 72 hours postinfection (hpi). Ultrastructural analyses showed that all altered structure function mitochondria, nucleus, rough endoplasmic reticulum Monolayers with variant highest number modified greatest statistically significant differences compared to those other variants. particles observed cytosol membrane 100 % at 48 hpi. Alpha mean particle diameter (79 nm), Gamma smallest (75 nm). had frequency per field hpi, while same Zeta hpi 24 respectively. The cycle threshold varied target protein, VOC, time infection. findings presented here demonstrate four VOCs evaluated caused ultrastructural cells, which more prominent when infection occured variant.