Bacteriophages as Surrogates for Studying Virus Stability on Antimicrobial Surfaces: A comparative Study with SARS-CoV-2

Abstract

The emergence of SARS-CoV-2 in Wuhan, China in 2019 has highlighted the importance of developing strategies to minimise the pandemic threats and prevent the transmission of pathogens. Since only a few laboratories have the resources and are capable of working and experimenting with SARS-CoV-2 in vitro and in vivo in a BSL-3 (Biosafety Level 3) laboratory, addressing questions using bacteriophages as surrogates can be a helpful tool. Bacteriophages already are well-established models for studying the behaviour of human pathogenic viruses. In this study, the suitability of the bacteriophages MS2 and Phi6 as surrogates for viruses like SARS-CoV-2 is addressed by testing their stability on antimicrobial surfaces like copper. The SARS-CoV-2 variants B.3 and XBB.1.5 were chosen as target viruses to compare the stability to bacteriophages. The findings revealed that the bacteriophages MS2 and Phi6 exhibited limited stability on copper. After one minute already, rapid reductions of viral titres were observed. Compared to that, both variants of SARS-CoV-2 displayed higher stability after the exposure to copper. But comparing the SARS-CoV-2 ancestral virus and the omicron variant XBB.1.5, it was observed that the latter exhibited an even higher stability on the copper surfaces, raising several important questions.The emergence of SARS-CoV-2 in Wuhan, China in 2019 has highlighted the importance of developing strategies to minimise the pandemic threats and prevent the transmission of pathogens. Since only a few laboratories have the resources and are capable of working and experimenting with SARS-CoV-2 in vitro and in vivo in a BSL-3 (Biosafety Level 3) laboratory, addressing questions using bacteriophages as surrogates can be a helpful tool. Bacteriophages already are well-established models for studying the behaviour of human pathogenic viruses. In this study, the suitability of the bacteriophages MS2 and Phi6 as surrogates for viruses like SARS-CoV-2 is addressed by testing their stability on antimicrobial surfaces like copper. The SARS-CoV-2 variants B.3 and XBB.1.5 were chosen as target viruses to compare the stability to bacteriophages. The findings revealed that the bacteriophages MS2 and Phi6 exhibited limited stability on copper. After one minute already, rapid reductions of viral titres were observed. Compared to that, both variants of SARS-CoV-2 displayed higher stability after the exposure to copper. But comparing the SARS-CoV-2 ancestral virus and the omicron variant XBB.1.5, it was observed that the latter exhibited an even higher stability on the copper surfaces, raising several important questions.