A novel and sensitive real-time PCR system for universal detection of poxviruses

Léa Luciani,Géraldine Piorkowski,Lucia Inchauste,Antoine Nougairède,Stéphane Priet,Olivier Ferraris,Stéphane Bertagnoli,Christophe Peyrefitte,Xavier De Lamballerie,Rémi Charrel

doi:10.1038/s41598-021-81376-4

Abstract

Success in smallpox eradication was enabled by the absence of non-human reservoir for smallpox virus. However, other poxviruses with a wider host spectrum can infect humans and represent a potential health threat to humans, highlighted by a progressively increasing number of infections by (re)emerging poxviruses, requiring new improved diagnostic and epidemiological tools. We describe here a real-time PCR assay targeting a highly conserved region of the poxvirus genome, thus allowing a pan-Poxvirus detection (Chordopoxvirinae and Entomopoxvirinae). This system is specific (99.8% for vertebrate samples and 99.7% for arthropods samples), sensitive (100% for vertebrate samples and 86.3% for arthropods samples) and presents low limit of detection (< 1000 DNA copies/reaction). In addition, this system could be also valuable for virus discovery and epidemiological projects.

Highlights

The successful global eradication of smallpox in 1980 was an unprecedented victory for humankind and preventive medicine, making the world free of one of its most dangerous diseases
This is illustrated by the gradual increase in numbers of infections byemergent members of the genus Orthopoxvirus, including Monkeypox[1,2], Cowpox[3], Camelpox and Buffalopox virus[4]
To establish a real-time PCR system able to detect any poxviruses, we first looked for a conserved gene within the entire Poxviridae family g enome[18]

Summary

Introduction

The successful global eradication of smallpox (caused by the Variola virus) in 1980 was an unprecedented victory for humankind and preventive medicine, making the world free of one of its most dangerous diseases. Vaccinia virus and Variola virus are both members of the genus Orthopoxvirus within the Chordopoxvirinae subfamily This triumph created a situation in which the subsequent cessation of vaccination has rendered the global human population vulnerable to (ortho)poxvirus infections. This is illustrated by the gradual increase in numbers of infections by (re)emergent members of the genus Orthopoxvirus, including Monkeypox[1,2], Cowpox[3], Camelpox and Buffalopox virus[4]. We report and validate the performance of a qPCR detection system, targeting a nucleotide sequence conserved in all poxviruses, and capable of detecting known pathogenic poxviruses and any other poxviruses from the Chordopoxvirinae and Entomopoxvirinae subfamilies

Methods

Results

Conclusion