Whole-Genome Sequencing of Pathogens in Saliva : A Target-Enrichment Approach for SARS-CoV-2

Outbreak analysis and transmission surveillance of viruses can be performed via whole-genome sequencing after viral isolation. Such techniques have recently been applied to characterize and monitor SARS-CoV-2 , the etiological agent of the COVID-19 pandemic. However, the isolation and culture of SARS-CoV-2 is time consuming and requires biosafety level 3 containment, which is not ideal for many resource-constrained settings. An alternate method, bait capture allows target enrichment and sequencing of the entire SARS-CoV-2 genome eliminating the need for viral culture. This method uses a set of hybridization probes known as "baits" that span the genome and provide sensitive, accurate, and minimal off-target hybridization. Baits can be designed to detect any known virus or bacteria in a wide variety of specimen types, including oral secretions. The bait capture method presented herein allows the whole genome of SARS-CoV-2 in saliva to be sequenced without the need to culture and provides an outline of bait design and bioinformatic analysis to guide a bioinformatician.