Viability of MS2 and Phi6 Bacteriophages on Carpet and Dust

  1. Nicholas Nastasi
  2. Nicole Renninger
  3. Ashleigh Bope
  4. Samuel J. Cochran
  5. Justin Greaves
  6. Sarah R. Haines
  7. Neeraja Balasubrahmaniam
  8. Katelyn Stuart
  9. Jenny Panescu
  10. Kyle Bibby
  11. Natalie M. Hull
  12. Karen C. Dannemiller

Reviewed by

Read the full article See related articles

Listed in

Log in to save this article

Abstract

Respiratory viral illnesses are commonly spread in the indoor environment through multiple transmission routes, including droplets, aerosols, and direct/indirect contact. Indoors, resuspension of dust from flooring is a major source of human exposure. However, it is critical to determine viral persistence on dust and flooring to better characterize human exposure. The goal of this work is to determine viral viability on two carpet types (cut and looped) and house dust over time and after four different cleaning methods. MS2 and Phi6 bacteriophages were used to represent non-enveloped and enveloped viruses, respectively. These viral surrogates were placed in an artificial saliva solution and nebulized onto carpet or dust. Viability was measured at various time points (0, 1, 2, 3, 4, 24, and 48 hours) and after cleaning (vacuuming, hot water extraction with stain remover, steam, and a disinfection spray). Viability decay was modeled as first-order. MS2 bacteriophages showed slower viability decay rates in dust (−0.11 hr -1 ), cut carpet (−0.20 hr -1 ), and looped carpet (−0.09 hr -1 ) compared to Phi6 (−3.36 hr -1 , -1.57 hr -1 , and - 0.20 hr -1 respectively). The difference between phages was statistically significant in dust and cut carpet (p<0.05). Viral RNA demonstrated minimal degradation that in most cases was not statistically different from zero over the 48 hours measured (p>0.05). Viable viral concentrations were reduced to below the detection limit for steam and disinfection for both MS2 and Phi6 (p<0.05), while vacuuming and hot water extraction with stain remover showed no significant changes in concentration from uncleaned carpet (p>0.05). This study used viral surrogates and did not model risk of viral transmission via dust. Overall, these results demonstrate that MS2 and Phi6 bacteriophages can remain viable in carpet and dust for several hours to days, and cleaning techniques with heat and disinfectants may be more effective than standard vacuuming for viral removal. Future work should model risk from exposure via dust and flooring for various viruses such as influenza, SARS-CoV-2, and RSV.

Abstract Figure

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2021.05.17.444479: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: Collection of dust for this study was approved by the Ohio State University Institutional Review Board (Study 2019B0457).
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line AuthenticationAuthentication: cDNA was reverse transcribed from RNA samples using the iScript cDNA Synthesis Kit (Biorad, Hercules, CA) according to the recommended reaction protocol on the ProFlex PCR System (Applied Biosystems, Forest City, CA).

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    All decay rate constants, regression coefficients and confidence intervals were calculated using GraphPad PRISM ver. 9 (GraphPad, San Diego, CA) fixing the y-intercept to zero.
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)
    Confidence bands represent the boundary for all possible lines and were determined and plotted using GraphPad PRISM ver. 9.
    GraphPad PRISM
    suggested: (GraphPad Prism, RRID:SCR_002798)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    In this study the relative humidity was maintained ∼30% to mimic realistic home environment conditions, however due to incubation limitations this humidity level varied between 40-90% early in the incubation depending on the sample (Figure S1). The variation between carpet fiber structures could change the moisture retention properties and thus impact the decay rates for MS2 and Phi6 bacteriophages. However, this variation in carpet fiber construction is realistic in real-world building environments and should be investigated further to examine its effect on viral-saliva droplet deposition and evaporation. Elevated humidity conditions in carpet dust are known to influence fungal growth [53,54] and this humidity may influence the viability and stability of viruses in carpet dust. Continued work is needed to fully understand how elevated humidity in carpet may impact the viability as well as the stability of SARS-CoV-2 and other viruses in dust. Differential viral removal efficacy of cleaning methods: Inactivation or removal of viruses from house dust or residential carpets is an important tool that can be used to reduce viral transmission in indoor environments. Vacuuming is a common housekeeping routine used to remove accumulated soils from carpet. This method reduced viable viruses on our carpet samples, when compared to carpet samples that were not cleaned, but the viable virus was still detectable in the carpet afterward. However, vacuuming, and hot water extraction remove...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1101/2021.05.17.444479v1 on bioRxiv