Exploring Oxford nanopore technology-based on-site SARS-CoV-2 genome sequencing

In a latest research posted to the medRxiv* preprint server, researchers carried out genomic sequencing of extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected samples. They aimed to establish the dominant variant, assess the mutation profile, and decide the sample-to-sequence turnover time.

Study: Rapid genome surveillance of SARS-CoV-2 and study of risk factors using shipping container laboratories and portable DNA sequencing technology. Image Credit: Tartila/Shutterstock
Research: Fast genome surveillance of SARS-CoV-2 and research of danger elements utilizing transport container laboratories and moveable DNA sequencing expertise. Picture Credit score: Tartila/Shutterstock

As well as, they decided the chance elements related to coronavirus illness of 2019 (COVID-19) mortality in residents of Bailiwick of Jersey, a United Kingdom (UK) island.

SARS-CoV-2 belongs to the B-betacoronavirus household (B-βCoV) of viruses. The virus incorporates single-stranded ribonucleic acid (RNA) together with proteins such because the spike (S), nucleocapsid (N), membrane (M), and envelope (E). Mutations within the amino acid sequences of those viral proteins give rise to new variants of concern (VOCs). The speedy emergence of novel variants has made it troublesome to manage the unfold of COVID-19. An understanding of the genetic elements would allow the formulation of improved vaccines and therapeutic methods to fight COVID-19.

In regards to the research

Within the current research, the researchers assessed the viral genome of COVID-19 sufferers and carried out an epidemiological evaluation to establish the chance elements related to COVID-19 mortality.

Major knowledge of 8,950 COVID-19 circumstances identified by reverse-transcription-polymerase chain response (RT-PCR) between September 2020 to August 2021 have been obtained by the Authorities of Jersey (GoJ) as a part of a well being surveillance program. Secondary knowledge was obtained from COVID-19 sufferers between June 2021 and July 2021, comprising the vaccination standing, signs, and journey historical past of all arrival passengers aged 11 years and above. Info on island residents who sought RT-PCR in case of optimistic signs or direct contact with COVID-19 sufferers was additionally obtained.

Oral-nasopharyngeal swabs have been collected from 154 sufferers and subjected to genetic sequencing on the GoJ OpenCell laboratory. As well as, 426 genetic sequences have been secondarily obtained from a pathological laboratory. The samples have been subjected to RT-PCR to synthesize complementary deoxyribonucleic acid (cDNA) and measure viral hundreds. The genomic sequences have been built-in with RT-PCR findings to evaluate the sample-to-sequence turnaround time. Viral a great deal of 6,540 samples with cycle threshold (Ct) numbers decrease than 30 have been analyzed.

Outcomes and dialogue

A complete of 12 genetic lineages have been recognized and grouped into the Delta sub-clades 21J and 21I. About 53% of the sequences contained T95I mutations whereas S: S943T and S: A222V mutations have been current in 9% and 25% of sequences, respectively. Extremely predominant S gene mutations noticed have been T19R, L452R, F157 R158G D614G, T478K, E156, and P681R. Probably the most prevalent mutations noticed within the viral S genome have been R158G (99.8%), G142D (99.8%), A222V (18.8%), and T95I(73.9%).  

Many of the sequences have been of the Delta VOC (B1.617.2 lineage). These findings recommend that the Delta VOC was the dominant variant in Jersey between June 2021 and September 2021. The mutations improve viral binding with the host angiotensin-converting enzyme 2 (ACE2) receptors resulting in elevated viral transmission and better COVID-19 incidence.

The sample-to-sequence turnaround time was roughly 30 hours. Affected person registration, swab assortment, and diagnostic evaluation took about 12 hours, whereas genome sequencing took 18 hours.

Asymptomatic circumstances have been larger in winter amongst elders whereas symptomatic circumstances have been predominantly noticed in youthful people (imply age 36 years) in summer season. Total, the variety of infections and hospitalizations was 4 instances larger in winter. The best COVID-19 mortality charge was noticed in these aged above 80 years (66.3%). Nevertheless, younger people remained optimistic for longer intervals. Moreover, the mortality charge was 21% larger in males. Total, viral titers have been larger in males, elders, and unvaccinated people.

Notably, males may very well be extra susceptible to COVID-19 mortality because of the larger expression of ACE2 receptors in males. Additionally, deaths attributable to COVID-19 may very well be larger in sufferers aged above 80 years because of the lower in immunity and improve in comorbidities with advancing age. Larger viral RNA titers in elders above 70 years are suggestive of elevated viral RNA in older age. Furthermore, the longer interval of an infection in kids may very well be attributable to their unvaccinated standing, as solely senior residents have been vaccinated within the preliminary vaccine rollout.


The research findings confirmed that high-coverage viral genomic sequencing may very well be carried out in close to real-time with the usage of cost-effective and moveable Oxford Nanopore Know-how (ONT) units. This supplies an awesome alternative for policymakers to generate on-site and speedy viral genomic sequences.

Nevertheless, the diagnostic parameters must be optimized to shorten the sample-to-sequence turnaround time. Future longitudinal research and analysis ought to deal with COVID-19 samples with Ct values above 30 that examine viral a great deal of a number of VOCs.

*Vital discover

medRxiv publishes preliminary scientific experiences that aren’t peer-reviewed and, due to this fact, shouldn’t be considered conclusive, information scientific apply/health-related conduct, or handled as established info.

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