Decontamination of Geobacillus Stearothermophilus using the Arca Aerosolized Hydrogen Peroxide decontamination system

Loren Benjamin Mead; Tanner Mathison; Garry Osborne; Anne Marie Richards

doi:10.1371/journal.pone.0273937

Peer Review History

Original SubmissionMay 1, 2022
16 Jun 2022 Decision Letter - Peter Setlow, Editor Transfer Alert This paper was transferred from another journal. As a result, its full editorial history (including decision letters, peer reviews and author responses) may not be present. PONE-D-22-12807Decontamination of Geobacillus Stearothermophilus Using the Arca Aerosolized Hydrogen Peroxide Decontamination SystemPLOS ONE Dear Dr. Loren, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Jul 31 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. 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The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf. 2. Thank you for stating the following in the Competing Interests section: [The authors of this publication are members of Abaton's Board of Directors, which could be perceived as a competing interest. However, the authors do not receive a salary or any gifts-in-kind for their service on the Board, and Abaton is a 501(c)3 non profit. The Arca device design has not, nor ever will be submitted for patent. The intention of the authors is to disseminate the design as an open source document for replication in locations where it might be of assistance. The authors further declare that they in no way financially or otherwise benefitted from the grant funding and personal donations made to Abaton.] Please confirm that this does not alter your adherence to all PLOS ONE policies on sharing data and materials, by including the following statement: "This does not alter our adherence to PLOS ONE policies on sharing data and materials.” (as detailed online in our guide for authors http://journals.plos.org/plosone/s/competing-interests). If there are restrictions on sharing of data and/or materials, please state these. Please note that we cannot proceed with consideration of your article until this information has been declared. Please include your updated Competing Interests statement in your cover letter; we will change the online submission form on your behalf. 3. Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. Additional Editor Comments: Dear Dr. Loren, Your manuscript has been reviewed by two experts in the field, and while both reviewers are positive about the manuscript, they make a few minor comments that should be attended to, as they will improve the manuscript. Sincerely, Peter Setlow [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: N/A ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The manuscript by Mead et al "Decontamination of Geobacillus Stearothermophilus using the Arca Aerosolized Hydrogen Peroxide decontamination system" is a well written description of a device that uses vaporized hydrogen peroxide to disinfect N95 respirators. The methods are straightforward and are consistent with previous literature that vaporized H2O2 is an effective disinfectant. The main issue to consider is that the authors repeatedly discuss this as an option for low resource areas at a cost of 2000. It is not clear from figure 2 how many masks fit in the device and what the throughput is. In table 1 many of those were high throughput set ups such that it is not an equitable comparison. Perhaps including the masks in Figure 2 would be helpful. A cost per N-95 might be more applicable as if one can only repurpose 20 per day even at 2000 it may not be cost effective especially as manufacturing and stockpiles have increased. It would be helpful in the discussion to discuss throughput (how many masks per day for a single unit) as well as cost in this context. Minor point The authors state sterility was demonstrated by clear TSB and lack of color change at 7 days. Unfortunately I was unable to access the cited reference (error code) for the steris procedure and the manufacturer of the BI strip is not provided. TSB turbidity requires significant growth and lack of turbidity is not equivalent to no growth. The media will not necessarily change color with small amounts of growth (perhaps this was a reference to a color indicator on the strip) Filtering the media and plating the filter to catch any organisms is one mechanism to capture small amount of organisms in a volume too large to plate. Some clarification of this procedure as well as the limit of detection for colony forming units would be helpful to the reader. It would also be helpful to note how much growth was seen with the positive control as well to confirm the log killing and disinfection achieved if we assume the TSB was in fact sterile. Reviewer #2: A very straightforward paper. Only a few minor comments. 1) l 42 - In light of ramping up a variety of responses to the pandemic that drove up supplies of PPE and drove down costs, might be helpful to give an estimate of the times/costs to process 1, 10, 100 etc M-95s would be helpful. 2) l-90 . Presumably these are G. stearothermophilus spores? Are these BIs the ones used for H2O2 sterilizers, as I believe these spores are not generally the ones most resistant to H2O2, although are for wet heat. 3) Since the TSB incubated with H2O2-treated BIs gave no obvious turbidity/color change, most spores have been killed. But what are the limits of this assessment? I could not access reference 23 to get any information about this, and thus it is not clear what the confidence in "sterility is. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0273937.r001
Revision 1
16 Aug 2022 Author Response Reviewer #1: The manuscript by Mead et al "Decontamination of Geobacillus Stearothermophilus using the Arca Aerosolized Hydrogen Peroxide decontamination system" is a well written description of a device that uses vaporized hydrogen peroxide to disinfect N95 respirators. The methods are straightforward and are consistent with previous literature that vaporized H2O2 is an effective disinfectant. The main issue to consider is that the authors repeatedly discuss this as an option for low resource areas at a cost of 2000. It is not clear from figure 2 how many masks fit in the device and what the throughput is. In table 1 many of those were high throughput set ups such that it is not an equitable comparison. Perhaps including the masks in Figure 2 would be helpful. A cost per N-95 might be more applicable as if one can only repurpose 20 per day even at 2000 it may not be cost effective especially as manufacturing and stockpiles have increased. It would be helpful in the discussion to discuss throughput (how many masks per day for a single unit) as well as cost in this context.  Response: The comment from Reviewer #1 regarding equitable comparisons of the devices is well-taken. The throughput rates for the commercially available systems are much larger than that of the Arca. However, while the marginal cost to clean an additional N95 is significantly lower for the large throughput commercially available options, the outsized cost of these solutions make them a non-starter for low-resource settings. Additionally, Abaton is a non-profit which provides the Arca devices for free to at-need institutions. The true costs to end users include the purchase of additional H2O2, electricity to run the Arca, and staffing. These are variable costs based on location and utility pricing. We have highlighted this point and included the throughput of the Arca in our updated discussion to better address the cost-effectiveness of the device.  Minor point The authors state sterility was demonstrated by clear TSB and lack of color change at 7 days. Unfortunately I was unable to access the cited reference (error code) for the steris procedure and the manufacturer of the BI strip is not provided. TSB turbidity requires significant growth and lack of turbidity is not equivalent to no growth. The media will not necessarily change color with small amounts of growth (perhaps this was a reference to a color indicator on the strip) Filtering the media and plating the filter to catch any organisms is one mechanism to capture small amount of organisms in a volume too large to plate. Some clarification of this procedure as well as the limit of detection for colony forming units would be helpful to the reader. It would also be helpful to note how much growth was seen with the positive control as well to confirm the log killing and disinfection achieved if we assume the TSB was in fact sterile. Response: This is a valid critique and therefore we have added to our discussion regarding the limitations of this study. The TSB growth medium testing provides a binary outcome of growth versus no growth. STERIS labs were unable to provide log kill information. Reviewer #2: A very straightforward paper. Only a few minor comments.  1) l 42 - In light of ramping up a variety of responses to the pandemic that drove up supplies of PPE and drove down costs, might be helpful to give an estimate of the times/costs to process 1, 10, 100 etc M-95s would be helpful.  Response: We have added the throughput of the Arca in our discussion to better evaluate the cost-effectiveness of the device.  2) l-90 . Presumably these are G. stearothermophilus spores? Are these BIs the ones used for H2O2 sterilizers, as I believe these spores are not generally the ones most resistant to H2O2, although are for wet heat. Response: That is correct, we used G. stearothermophilus spores. According to CDC recommendations, G. stearothermophilus is the appropriate biologic indicator for assessing sterilization with H2O2 devices. Please see the link below: https://www.cdc.gov/infectioncontrol/guidelines/disinfection/sterilization/sterilizing-practices.html   3) Since the TSB incubated with H2O2-treated BIs gave no obvious turbidity/color change, most spores have been killed. But what are the limits of this assessment? I could not access reference 23 to get any information about this, and thus it is not clear what the confidence in "sterility is. Response: This is a valid critique and therefore we have added to our discussion regarding the limitations of this study. The TSB growth medium testing provides a binary outcome of growth versus no growth. STERIS labs were unable to provide log kill information. Attachments Attachment Submitted filename: Response to Reviewers.pdf https://doi.org/10.1371/journal.pone.0273937.r002
18 Aug 2022 Decision Letter - Peter Setlow, Editor Decontamination of Geobacillus Stearothermophilus Using the Arca Aerosolized Hydrogen Peroxide Decontamination System PONE-D-22-12807R1 Dear Dr. Mead, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Peter Setlow Academic Editor PLOS ONE Additional Editor Comments (optional): All comments made in the previous review have been answered appropriately, and the data in the manuscript have been presented objectively and in an unbiased manner, and the latter is also true of all conclusions made in the manuscript. Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #2: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #2: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #2: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #2: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #2: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #2: (No Response) ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #2: No ******** https://doi.org/10.1371/journal.pone.0273937.r003
Formally Accepted
1 Sep 2022 Acceptance Letter - Peter Setlow, Editor PONE-D-22-12807R1 Decontamination of Geobacillus Stearothermophilus Using the Arca Aerosolized Hydrogen Peroxide Decontamination System Dear Dr. Mead: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Peter Setlow Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0273937.r004

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