Bacterial Contamination in Health Care Centers: Differences between Urban and Rural Settings

Round 1

Reviewer 1 Report

Review: Bacterial contamination in Health Care Centers: Differences between urban and rural settings

This study investigated the degree of bacterial contamination occurring in health care centers in Portugal, and confirmed bacterial air pollution such as aerobic mesophilic bacteria and bacteria in urban and rural health care centers.

In this paper, each room (treatment room, vaccination room, medical room, etc.) in urban and rural health care centers was investigated relatively on bacterial contamination and bacterial propagation and types of bacteria according to temperature, humidity, CO2.

In the previous review, insufficient numbers of experimental groups, identification of bacterial contamination pathways, and collection of large numbers of samples were requested to be corrected, and appropriate corrections were made by the author.

According to that, it is sufficient to publish this paper in this journal by clearly measuring the level of bacterial contamination in urban and rural areas through sufficient reviews and data.

Author Response

The authors are grateful for the review of the article and all comments.

Reviewer 2 Report

The article titled "Bacterial contamination in Health Care Centers: Differences between urban and rural settings", has had significant improvements made following the revisions made by the authors. The article describes a study, where the authors analysed the bacterial species identified in dust and on surfaces from two primary health care centres (PHCC) in Portugal. However, some improvements can still be made which will make the article stronger.

Major Comments: 

The authors have made significant improvements in their introduction regarding why they decided to search specifically for Pseudomonas aeruginosa; however, their argument is primarily focused on the identification of MDR P. aeruginosa and it's possible impact on workers' and patients' health. Given the fact that no P. aeruginosa species were identified in this study, I would not give so much focus on MDR pseudomonas and rather focus on why pseudomonas in general is such a large problem in PHCCs. 

In addition, the authors mentioned that although the Urban PHCC had the highest concentrations of bacteria in most samples, it was the Rural PHCC which had the greatest number of pathogenic/BSL level 2 species. I think it highly relevant to discuss, that although the rural PHCC had lower concentrations of bacteria, they had greater number of pathogens, and that future legislation regarding Portuguese indoor air quality should not only be focused on quantitative results, such as concentrations of bacteria, but also on the specific species present. 

Minor comments: 

There are still some abbreviations which are misspelled (ex. line 32, "UFC.m^-2). In addition, I am not sure if this is a formatting error during submission, but in the cases where there is supposed to be a "dot" between units, there is a period "." instead. 

In lines 60-64, the authors mention that health care facilities have pieces of equipment which can release Legionella. Please give a few examples of these pieces of equipment. 

Line 78-80, this sentence is confusing and the grammar needs to be improved

Line 83, what is meant by "intitled high-risk" 

Lines 102-103, there are 6 references referred to here. Are all 6 truly needed? 

Line 103-105, this was a comment I had in the previous submission regarding how airborne bioburden has not been studied in PHCCs, which I feel still has not been answered. The authors responded that "the present study is included in a larger, study, unique in Portugal, mentioned in that reference". I do not feel that this response satisfactorily answers my comment that this has been previously done. I would rewrite this sentence to state that "airborne bioburden assessment in Portuguese PHCCs has only been done in a few limited studies...."

Line 236, were these isolates of Staphylococcus or of other species?

Figure 1, the units are missing from the X-axis of the plot!

Figure 2, thank you for changing the pie chart to a heatmap. However, there are several species names which are capitilised incorrectly (eg. Staphylococcus Aureus). I would also either change the order of the species so that it is alphabetical, or make the order from the most common species, to the least common. At the moment the order seems random

Table 3. For the number of isolates, please include the total number of isolates from that species (ex. 15/XX (2.8%)). The decimal sign must also be a ".", not a ","

Table 3, in the abbreviations, the incorrect abbreviation for gentamicin is given (the authors have written CN rather than GEN). 

Line 445, the way this sentence is currently structured, it makes it appear that S. aureus was not detected in any of the sampled materials, even though it was found in the air samples. I would rephrase this section to make it clear that it was detected, but just not in the swabs. 

Lines 561-565, per the major comment listed above, please expand on this section regarding how future legislation might have to consider not only the concentration of bacteria, but also the species composition in indoor air. 

 

Author Response

The authors are grateful for the review of the article and all comments. We attached our reply.

Author Response File: Author Response.docx

Reviewer 3 Report

The authors made corrections based on my previous suggestions on the manuscript. I now recommend this for publication. 

Author Response

The authors are grateful for the review of the article and all comments.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Review: Bacterial contamination in Health Care Centers: Differences between urban and rural settings

This study investigated the degree of bacterial contamination occurring in health care centers in Portugal, and confirmed bacterial air pollution such as aerobic mesophilic bacteria and bacteria in urban and rural health care centers.

In this paper, each room (treatment room, vaccination room, medical room, etc.) in urban and rural health care centers was investigated relatively on bacterial contamination and bacterial propagation and types of bacteria according to temperature, humidity, CO2.

As a result, this paper has clearly investigated the degree of contamination of bacteria in  health care centers, and it is considered that it can be published in the journal of atmosphere  as it has a direct effect on indoor air quality.

The following is a summary of the items that should be added to this paper.

1. As the number of health care centers that are experimental groups is small, it is thought that more accurate results can be obtained by adding more experimental groups

2. The research method, collection of information, etc. are relatively clear, and the calculated value of the experimental results is good, but the structure and maintance of health care facilities in urban and rural areas are different, so it is necessary to understand the path of penetration and spread of bacteria.

3. The collection time of the settled dust is limited to 10 minutes and there are not many experiments, so it is difficult to secure reliability, so a larger number of samples is recommanded.

 

It is sufficent to publish this paper in this journal by clearly measuring the level of bacterial contamination in urban and rural areas through sufficient reviews and data. However, if more experimental groups, the number of experiments, and clear environmental factors are considered, the paper can be better.

In conclusion, this paper is expected to be published in the Atmosphere journal because the English expression is clear and the research content is clear. This paper can be used as an important data for understanding indoor air quality in medical facilities such as hospitals with many patients who are susceptible to bacterial contamination in the future. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

In the article titled "Bacterial contamination in health care centers: differences between urban and rural settings" that authors a study, where they compared the bacterial burden present in two primary health care centres, one which was in an urban area, and the other which was rural. The authors utilised a variety of sampling strategies, for collecting airborne bacteria, settled dust, settling dust, and performing biochemical testing to analyse the antibiotic resistance within their bacterial isolates. 

The study the authors have performed is intersting, however the manuscript could be improved before it is accepted, particularly in the introduction and discussion regarding the choice to screen specifically MRSA, P. aeruginosa, and Legionella sp, in addition to why the difference in the urban and rural setting would affect patients' or workers' exposure. 

General comments:

Only write the first letter of the genus name after you have already mentioned it. In several locations, such as lines 530-538, the word Staphylococcus is written again, and again, and again. After the first Staphylococcus, write S. and then the species name 

Check the abbreviations. Example on line 101, the authors write "UFC.m^-3". Please go through the manuscript again and fix these typos 

Specific comments: 

Introduction:

Line 58: delete the word "and" before "Bordetella pertussis"

Lines 63-64: Legionella should be in italics

Line 67 (amongst others): delete "Staphylococcus" and replace with "S."

Line 73: rather than stating "methicillin" I would prefer if you would use the class of drug (beta-lactam) rather than one of the examples of that drug class

Line 90: the authors mention that this type of study has not been done in PHCC in Portugal, but there are some written by the authors themselves? Eg: Biodurden in health care centers: is the compliance with Portuguese legislation enough to prevent and control infection?

Lines 112-114: while the authors have given logical reasons as to why they want to study exposure to MRSA, and Legionella, it was very surprising to read that they specifically wanted to assess exposure to P. aeruginosa as no reasoning was given prior as to why P. aeruginosa would be a likely problem in Portuguese PHCCs. 

Lines 136-137: it is unclear as to what "tilting flag and full openness" referers to regarding the windows. Perhaps use another expression?

Methods: 

Line 231: "performed exclusively ON (not in) surfaces...."

Results: 

Lines 333-341 and 359-373: although the rural PHCC failed in compliance with the Portuguese legislation regarding the concentration of airborne bacteria, wouldn't it be a better comparison, if the authors looked into the actual species composition of the two centres? Which centre had more pathogens/potential pathogens? 

Figure 2: change these Pie-charts to a heatmap as it is unfortunately very difficult to make out the differences between the low abundant species. 

Table 3: how common is ticarcillin resistance? Is this a common problem in Staphylococcus species. In addition, in how many isolates did you find resistance? Please show the numbers (eg. 4/39, or 1/20), as it will give a better understanding regarding how common this resistance was. 

Tables 4 and 5: I would merge these two tables together (so make another column on the left, where it is written Urban/Rural PHCC) OR place them both in the supplement, as they are both very similar and not extraordinarily informative. 

Discussion: 

Lines 461-462: since this study only analysed the differences between a single PHCC in a rural area, and a single PHCC in an urban area, I would not say that this study compared "the differences in rural and urban contexts", as the sample size is too small to make a proper assessment between these two location types. 

Lines 471-473: The authors state that the Portuguese legislation does not take into consideration clinically relevant bacteria regarding the acceptable limits for indoor air bioburden. However, as I (and others) are unfamiliar with this legislation piece, does it mention a specific limit for fungal spore concentrations? In addition, regarding building exposure, it might be more appropriate to consider fungal exposure rather than bacterial exposure. 

Lines 480-481: consider deleting some of the references

Lines 482-486: this sentence is very long and confusingly written. I would suggest breaking into 2 sentences and changing the phrasing. 

Lines 487-494: again, confusingly written and there seems to be two main topics, the urban/rural settings, and the choice of methodology. I would separate the two into different sentences or paragraphs. 

Line 496: choice one of the five citations, having five is a bit excessive.

Lines 508-521: Could you perhaps briefly discuss the disadvantages (or advantage) regarding using biochemical analyses for identifying your cultured CFUs, rather than using something like NGS, MALDI-TOF, qPCR, etc? 

Line 520: the species is "Stenotrophomonas maltophilia" not "Stenotrophomonas baltophilia"

Lines 522-526: are there any European studies you can cite? Eg. "No apparent transmission of live-stock associated methicillin resistant Staphylococcus aureus CC398 in a survey of staff at a regional Danish hospital"

Line 530-532: the authors state that the most common indoor bacterial species are several staphyloccci, but they cite a single article which was not a review, but a research paper? I would recommend they cite a different paper. 

Line 537-538: how often is ticarillin used in health care settings? 

Conclusions:

Did one location versus the other have a higher concentration of bacterial pathogens? that would be more of interest than just showing the raw concentration values and be of greater interest for not only the people working and being treated at these areas, but would also help to recommend changes for future guidelines. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Atmosphere_review_Manuscript # 1_1109753_March 2021

Overall, the manuscript is very well written – clear, concise, scientific and professional English language has been used throughout. The data carries merit in improving our understanding of bacterial contamination in healthcare centers in Portugal.

 

Please see my comments/ suggestions below for the improvement of the manuscript.

 

ABSTRACT: LINE 19 – Change ‘access’ to ‘study’

 

INTRODUCTION:

Line 67 - 69: needs citations

Lines 69-71: needs additional citations. This is a very broad statement, this should be backed up with more than one citation.

Lines 78-80: same as above, needs more citations as this is a very broad statement

METHODS:

Lines 116-120: Study site could use a map. Could the authors provide a map with the locations of the sites studies?

Question: How often were these sites sampled? This needs to be included in the sampling descriptions.

Line 178: How long were filters kept at 4C until processing? This does not look like an appropriate temperature for long term storage of biomass filters.

Lines 218 – 226: the antimicrobial resistance analysis needs more description: how many total isolates were tested for resistance?

 

RESULTS: On 3.7: more data is needed on the resistance analysis: percentages are always better to display resistance data, not in the format shown in table 3. How many isolates were tested? What percentage were resistant? How were isolates selected for resistant analysis?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf