Detection of coronaviruses, SARS-CoV-2 and MERS-CoV, in human and camel samples using different real-time RT-PCR kits

Abstract

Coronaviruses are enveloped, large positive-sense, and single-stranded RNA viruses. Four coronavirus genera have been identified: alpha, beta, gamma, and delta. Non-structural proteins make up two-thirds of the coronavirus genome, and some of these (ORF1ab) are essential to create the replicase-transcriptase complex. The remaining coronavirus genome encodes four major structural proteins (S, E, M, and N). Coronaviruses infect both animals and humans, and the emergences of SARS-CoV, MERS-CoV, and SARS-CoV-2 highlight the viruses' importance as emerging pathogens. Accurate viral detection is crucial for treating cases and controlling diseases.
MERS is a viral respiratory infection in humans and dromedary camels caused by MERS-CoV that was identified in 2012 at Saudi Arabia. SARS -CoV-2, the causal agent of coronavirus disease 2019 (COVID-19), was first identified in Wuhan, China, in December 2019 and then spread globally, resulting in a pandemic. Many countries performed fast large-scale testing as a way to halt its spread. The National Veterinary Institute (NVI) of Ethiopia was among the organizations that took part in the COVID-19 testing campaign during the pandemic.
The real-time reverse transcription polymerase chain reaction (real-time RT-PCR) is the gold standard method for diagnosing suspected cases of COVID-19 and MERS-CoV. These methods, which target viral ribonucleic acid (RNA), are currently the primary approach for directly identifying the virus.
In this study, three real-time RT-PCR assays were employed to detect SARS-CoV-2 in human samples: two developed by CDC China for ORF1ab and the N genes, and one ORF1ab-based assay (BGI, China), and one RT-PCR assay developed by Charité laboratory (Berlin, Germany) for E gene targets. The other two RT-PCR assays developed by Corman et al., 2012 targeting MERS-CoV’s upstream E (UpE) gene and ORF1a gene were used to screen and confirm MERS-CoV in camel swab samples. The uniplex, duplex, and triplex RT-PCR assays were assessed following the recommended protocols.