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. 2021 Jan 11;13(1):58-71.
doi: 10.3390/idr13010008.

Reducing Spread of Infections with a Photocatalytic Reactor-Potential Applications in Control of Hospital Staphylococcus aureus and Clostridioides difficile Infections and Inactivation of RNA Viruses

Abeer Gharaibeh  1   2   3 , Richard H Smith  1   3 , Michael J Conway  4
Affiliations

Reducing Spread of Infections with a Photocatalytic Reactor-Potential Applications in Control of Hospital Staphylococcus aureus and Clostridioides difficile Infections and Inactivation of RNA Viruses

Abeer Gharaibeh et al. Infect Dis Rep. .

Abstract

Contaminated surfaces and indoor environments are important sources of infectious spread within hospital and non-hospital facilities. Bacterial infections such as infections with Clostridioides (formerly Clostridium) difficile (C. difficile) and Staphylococcus aureus (S. aureus) and its antibiotic resistant strains continue to pose a significant risk to healthcare workers and patients. Additionally, the recent emergence of the coronavirus disease 2019 (COVID-19) pandemic, which is caused by the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlights the need for safe and effective methods to decontaminate surfaces to control infection spread in hospitals and the community. To address these critical needs, we tested a photocatalytic reactor decontamination method to disinfect contaminated surfaces in a hospital and a laboratory setting. By placing the reactor in a test hospital room, growth of S. aureus and C. difficile were significantly reduced compared with a control room. Additionally, using a model enveloped positive-sense single-stranded RNA virus, dengue virus type 2 (DENV2), we showed that the use of the photocatalytic reactor reduces viral infectivity. Collectively, the results demonstrate the potential utility of photocatalytic reactors in reducing the spread of highly contagious bacterial and viral infections through contaminated surfaces and environments.

Keywords: C. difficile; COVID-19; MRSA; RNA virus; Staphylococcus aureus; coronavirus; dengue virus; infection control; photocatalytic oxidation; photocatalytic reactor.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
The photocatalytic reactor setup in the hospital room. (A) The photocatalytic reactor. (B) Sterile stainless steel carriers were individually placed in sterile petri dishes and affixed to the bottom of each petri dish with adhesive and placed at multiple locations.
Figure 2
Figure 2
The photocatalytic reactor treatment reduces growth of S. aureus and C. difficile in hospital rooms. (A) Eleven samples containing S. aureus were placed in the testing room and three samples were placed in the control room. The graph represents the average log CFU/carrier values in the testing room compared to the control. The Student’s t-test analysis data showed that there was a significant reduction in the log CFU of S. aureus in the testing room after 24 h of treatment (M = 1.35, SD = 0.22) compared to the control (M = 3.92, SD = 0.60, * p < 0.001). (B) A representative graph for the percentage of S. aureus growth reduction in the testing room compared to the control. There was an average 99.86% (95% CI: 99.8 to 99.9%) reduction in bacterial growth in the testing room compared to the control. (C) Five samples containing C. difficile spores were placed in the testing room and three samples were placed in the control room. The graph represents the average log CFU/carrier values of the samples in the testing room compared to the control. Two sample t-test analysis data showed that there was a significant reduction in the log CFU of C. difficile in the testing room after 48 h of treatment (M = 0.7, SD = 0.51) compared to the control (M = 2.8, SD = 0.28, * p < 0.001). (D) A representative graph for the percentage of C. difficile reduction in the testing room compared to the control. There was an average 99.2% (95% CI: 98.1 to 99.7%) reduction in bacterial growth in the samples that were placed in the testing room compared to the control.
Figure 3
Figure 3
Inactivation of DENV2 with the photocatalytic reactor following 6-h exposure in a biosafety cabinet. (A) Viral growth assessed after the viral samples were treated with photocatalysis and inoculated into Aag2 cells. Three samples were used in each group. The Student’s t-test analysis showed that there was a significant reduction (* p < 0.05) in the average FFU/mL value in the treated samples (M = 433, SD = 208) compared to the control (M = 2200, SD = 200, p = 0.0004). (B) A representative graph for the average percentage of reduction in FFU/mL values after six hours of exposure to the photocatalytic treatment which was 83.5% (95% CI: 74.5 to 92.5%). (C) Representative digital images of DENV2-positive foci from the control and treated samples were taken at 20× magnification using an Evos Core inverted microscope.
Figure 4
Figure 4
Inactivation of DENV2 with the photocatalytic reactor outside the biosafety cabinet at 6, 12, 18, and 24-h timepoints. (A) Image of the photocatalytic reactor placed on the ground next to a biosafety cabinet. Four 96-well plates (three samples in each one) in total were placed inside the biosafety cabinet in the testing room. The fifth 96-well plate containing three samples was placed in the control room. Plates in the biosafety cabinet were removed and placed along with the fifth plate 6, 12, 18, and 24 h post-treatment. (B) DENV2 viral growth after exposure to the photocatalytic reactor treatment for 6, 12, 18, and 24 h compared to the control. Multiple Student’s t-test analyses of each treatment and control groups showed that there were significant reductions (* p < 0.05) in infectivity of DENV2 in the treated samples (p = 0.0326 (M = 2173, SD = 412), p = 0.001 (M = 747, SD = 356), p = 0.0002 (M = 280, SD = 191), and p = 0.0001 (M = 47, SD = 81) after 6, 12, 18, and 24 h, respectively) compared to the control (M = 3180, SD = 354). (C) A representative graph for average percentages of reduction in infectivity which were 31.7% (95% CI: 17 to 46.4%), 76.5% (95% CI: 63.8 to 89.2%), 91.2% (95% CI: 84.4 to 98%), and 98.5% (95% CI: 95.7 to 100%) after 6, 12, 18, and 24 h of treatment, respectively. (D) Representative digital images of DENV2-positive foci from the control and treated samples were taken at 20× magnification using an Evos Core inverted microscope.
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References

    1. Dancer S.J. Controlling Hospital-Acquired Infection: Focus on the Role of the Environment and New Technologies for Decontamination. Clin. Microbiol. Rev. 2014;27:665–690. doi: 10.1128/CMR.00020-14. - DOI - PMC - PubMed
    1. Peyrony O., Marbeuf-Gueye C., Truong V., Giroud M., Rivière C., Khenissi K., Legay L., Simonetta M., Elezi A., Principe A., et al. Accuracy of Emergency Department Clinical Findings for Diagnosis of Coronavirus Disease 2019. Ann. Emerg. Med. 2020;76:405–412. doi: 10.1016/j.annemergmed.2020.05.022. - DOI - PMC - PubMed
    1. Magill S.S., Edwards J.R., Bamberg W., Beldavs Z.G., Dumyati G., Kainer M.A., Lynfield R., Maloney M., McAllister-Hollod L., Nadle J., et al. Multistate Point-Prevalence Survey of Health Care—Associated Infections. N. Engl. J. Med. 2014;370:1198–1208. doi: 10.1056/NEJMoa1306801. - DOI - PMC - PubMed
    1. Centers for Disease Control and Prevention The Direct Medical Costs of Healthcare-Associated Infections in U.S. Hospitals and the Benefits of Prevention. [(accessed on 25 October 2020)]; Available online: https://stacks.cdc.gov/view/cdc/11550.
    1. Kavanagh K.T., Abusalem S., Calderon L.E. The incidence of MRSA infections in the United States: Is a more comprehensive tracking system needed? Antimicrob. Resist. Infect. Control. 2017;6:34. doi: 10.1186/s13756-017-0193-0. - DOI - PMC - PubMed

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