Differential Effects of Antiseptic Mouth Rinses on SARS-CoV-2 Infectivity In Vitro.

Chuan Xu,Kenneth Markowitz,Daniel H Fine,Eileen R Hoskin,Carla Cugini,Annie Wang,Theresa L Chang

doi:10.3390/pathogens10030272

Chuan Xu, Kenneth Markowitz + Show 5 more

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https://doi.org/10.3390/pathogens10030272

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Abstract

Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) is detectable in saliva from asymptomatic individuals, suggesting a potential benefit from the use of mouth rinses to suppress viral load and reduce virus spread. Published studies on the reduction of SARS-CoV-2-induced cytotoxic effects by mouth rinses do not exclude antiseptic mouth rinse-associated cytotoxicity. Here, we determined the effect of commercially available mouth rinses and antiseptic povidone-iodine on the infectivity of replication-competent SARS-CoV-2 viruses and of pseudotyped SARS-CoV-2 viruses. We first determined the effect of mouth rinses on cell viability to ensure that antiviral activity was not a consequence of mouth rinse-induced cytotoxicity. Colgate Peroxyl (hydrogen peroxide) exhibited the most cytotoxicity, followed by povidone-iodine, chlorhexidine gluconate (CHG), and Listerine (essential oils and alcohol). The potent antiviral activities of Colgate Peroxyl mouth rinse and povidone-iodine were the consequence of rinse-mediated cellular damage when the products were present during infection. The potency of CHG was greater when the product was not washed off after virus attachment, suggesting that the prolonged effect of mouth rinses on cells impacts the antiviral outcome. To minimalize mouth rinse-associated cytotoxicity, mouth rinse was largely removed from treated viruses by centrifugation prior to infection of cells. A 5% (v/v) dilution of Colgate Peroxyl or povidone-iodine completely blocked viral infectivity. A similar 5% (v/v) dilution of Listerine or CHG had a moderate suppressive effect on the virus, but a 50% (v/v) dilution of Listerine or CHG blocked viral infectivity completely. Mouth rinses inactivated the virus without prolonged incubation. The new infectivity assay, with limited impacts of mouth rinse-associated cytotoxicity, showed the differential effects of mouth rinses on SARS-CoV-2 infection. Our results indicate that mouth rinses can significantly reduce virus infectivity, suggesting a potential benefit for reducing SARS-CoV-2 spread.

Highlights

This article is an open access articleSevere acute respiratory syndrome-related coronavirus (SARS-CoV-2), a non-segmented positive-strand RNA enveloped virus, is the causative agent of coronavirus disease 19(COVID-19)
Previous studies were conducted to assess the antiseptic effect of povidoneiodine on several respiratory viruses, including SARS-CoV, Middle East Respiratory Syndrome (MERS)-CoV, and influenza A
Published data on the effect of mouth rinses on SARS-CoV-2 infection did not distinguish the impact of mouth rinses on cell viability in efforts to determine the direct effects of mouth rinses on viral infection [18,19,20]

Summary

Introduction

This article is an open access articleSevere acute respiratory syndrome-related coronavirus (SARS-CoV-2), a non-segmented positive-strand RNA enveloped virus, is the causative agent of coronavirus disease 19(COVID-19). Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2), a non-segmented positive-strand RNA enveloped virus, is the causative agent of coronavirus disease 19. The single-stranded positive-sense viral RNA is associated with nucleocapsid proteins [4,5]. Targeting viral components, including the membrane (envelope), surface spike proteins, and nucleic acids, to inactive viruses may reduce transmission. Evidence indicates that transmission of SARSCoV-2 occurs through virus-containing secretions, such as saliva and respiratory secretions, or their droplets [6]. Salivary SARS-CoV-2 viral load is highest during the first week after symptom onset [7], and individuals with SARS-CoV-2 infection shed virus and can remain asymptomatic for a prolonged period [8,9], highlighting the importance of developing a strategy to prevent virus spread in the general population. There is an urgent need for evidence-based practices to protect patients and healthcare workers in the dental office and elsewhere when salivary droplets and aerosols are generated during dental treatment when masks for patients are not an option

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