Description of nasopharyngeal bacterial pathogens associated with different SARS-CoV-2 variants.

The emergence of the coronavirus pandemic facilitated the acquisition of mutations in the SARS-CoV-2 genome, resulting in the appearance of new variants over the past three years. We previously identified several taxa associated with the clinical outcome of COVID-19 disease in a retrospective study involving 120 patients (infected patients and negative subjects). However, little is known about whether the different variants could influence variations in the composition of the nasopharyngeal microbiota.

High Throughput SARS-CoV-2 Genome Sequencing from 384 Respiratory Samples Using the Illumina COVIDSeq Protocol.

The emergence of the Coronavirus Disease 2019 (COVID-19) pandemic has fostered the use of high-throughput techniques to sequence the entire severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome and track its evolution. The present study proposes a rapid and relatively less expensive sequencing protocol for 384 samples by adapting the use of an Illumina NovaSeq library to an Illumina MiSeq flow cell instrument. The SARS-CoV-2 genome sequences obtained with Illumina NovaSeq and those obtained using MiSeq instruments were compared with the objective to validate the new, modified protocol.

Simultaneous SARS-CoV-2 Genome Sequencing of 384 Samples on an Illumina MiSeq Instrument through Protocol Optimization.

In the present study, we propose a high-throughput sequencing protocol using aNextera XT Library DNA kit on an Illumina MiSeq instrument. We made major modifications to this library preparation in order to multiplex 384 samples in a single Illumina flow cell. To validate our protocol, we compared the sequences obtained with the modified Illumina protocol to those obtained with the GridION Nanopore protocol.

The emergence, spread and vanishing of a French SARS-CoV-2 variant exemplifies the fate of RNA virus epidemics and obeys the Mistigri rule.

The nature and dynamics of mutations associated with the emergence, spread, and vanishing of SARS-CoV-2 variants causing successive waves are complex. We determined the kinetics of the most common French variant ("Marseille-4") for 10 months since its onset in July 2020. Here, we analyzed and classified into subvariants and lineages 7453 genomes obtained by next-generation sequencing.