Prevalence and Virulence of Commensal Pseudomonas Aeruginosa Isolates from Healthy Individuals in Southern Vietnam (2018–2020)

Round 1

Reviewer 1 Report

The authors developed the concept of to investigate the prevalence of Pseudomonas aeruginosa (P. aeruginosa) in healthy humans, its virulence, and the risk factors of colonization.

This concept can overcome certain restrictions and limitations of existing methods. 609 Vietnamese volunteers participated in this study, who had no acute infection or disease symptoms at the time of sample collection.

The authors introduced new mathematical modeling and its application in real-life problems.

This paper contains new and interesting results. This paper is well written and may be accepted subject to the revision.

1. Please revise Abstract and add motivation of the proposed work.

2. Please add advantages and limitations of the proposed work. 

3. In Section 2, Materials and Methods should be further improved with illustrations and more discussion.

4. Please add a comparison analysis of proposed approach with existing approaches. The authors can study the following recent articles.

https://www.mdpi.com/2073-8994/14/12/2538

https://www.mdpi.com/2073-8994/14/10/2216

5. Section 3 is Excellent. The authors can further improve discussion and comparison.

6. Literature review and References should be improved.

7. Please read paper and correct some typos, spaces, captions, dots, and commas.

Author Response

Dear Reviewers

Thank you for your comments. We would like to submit the revised version of the manuscript entitled “Prevalence and virulence of commensal Pseudomonas aeruginosa isolates from healthy individuals in Southern Vietnam (2018-2020)”. The edit tracking was turned on, and the edited parts were highlighted in the revised manuscript.

Below is the point-to-point response to your comment

The authors developed the concept of to investigate the prevalence of Pseudomonas aeruginosa (P. aeruginosa) in healthy humans, its virulence, and the risk factors of colonization.

This concept can overcome certain restrictions and limitations of existing methods. 609 Vietnamese volunteers participated in this study, who had no acute infection or disease symptoms at the time of sample collection.

The authors introduced new mathematical modeling and its application in real-life problems.

This paper contains new and interesting results. This paper is well written and may be accepted subject to the revision.

1. Please revise Abstract and add motivation of the proposed work.

We have revised the abstract and motivation of the proposed work has been added in the introduction part of the abstract.

2. Please add advantages and limitations of the proposed work.

We have revised the conclusion, in which the advantages and limitations were shown.

3. In Section 2, Materials and Methods should be further improved with illustrations and more discussion.

We have revised the Material and Methods part.

4. Please add a comparison analysis of proposed approach with existing approaches. The authors can study the following recent articles.

https://www.mdpi.com/2073-8994/14/12/2538

https://www.mdpi.com/2073-8994/14/10/2216

We have not performd mathematical modeling and comparison analysis

5. Section 3 is Excellent. The authors can further improve discussion and comparison.

Thank you very much! We have revised the discussion part.

6. Literature review and References should be improved.

We have revised the literature review and references.

7. Please read paper and correct some typos, spaces, captions, dots, and commas.

We have re-read the paper and corrected the writing mistakes.

Reviewer 2 Report

In this paper, the authors examined the distribution and virulence of commensal P. aeruginosa samples from individuals in Southern Vietnam. They found 20 P. aeruginosa isolates and 19 participants colonized with P. aeruginosa. In addition, they showed that the P. aeruginosa isolates had good ability for the synthesis of biofilm, pyocyanin and siderophores. I have some comments and questions for the paper.

Line 44-45, relevant reference(s) is needed here for the introduction of virulence factors.

Line 51-52, relevant reference(s) is needed here for the introduction of pyocyanin.

Line 73-74, I suggest the authors addressing why they collected throat, naris and outer ear swab samples, not the others here. 

Line 82, “oprL” italic

Line 124, “In case of siderophores” not italic

Line 147-150, relevant reference(s) is needed here for the introduction of oprL.

Line 165-169, could the authors discuss why the throat was primarily colonized by P. aeruginosa here?

In Table 3, it seems that biofilm of commensal P. aeruginosa isolates has a big difference from P. aeruginosa ATCC 9027, while the other virulence factors are quite similar between commensal P. aeruginosa isolates and P. aeruginosa ATCC 9027. Could the authors give some explanations?

In Fig1C, it’s a little confusing for C2, because nothing is observed here. 

Author Response

Dear Reviewers

Thank you for your comments. We would like to submit the revised version of the manuscript entitled “Prevalence and virulence of commensal Pseudomonas aeruginosa isolates from healthy individuals in Southern Vietnam (2018-2020)”. The edit tracking was turned on, and the edited parts were highlighted in the revised manuscript.

Below is the point-to-point response to your comment.

In this paper, the authors examined the distribution and virulence of commensal P. aeruginosa samples from individuals in Southern Vietnam. They found 20 P. aeruginosa isolates and 19 participants colonized with P. aeruginosa. In addition, they showed that the P. aeruginosa isolates had good ability for the synthesis of biofilm, pyocyanin and siderophores. I have some comments and questions for the paper.

Line 44-45, relevant reference(s) is needed here for the introduction of virulence factors.

We have added the references:

[9] Liao, C.; Huang, X.; Wang, Q.; Yao, D.; Lu, W. Virulence Factors of Pseudomonas Aeruginosa and Antivirulence Strategies to Combat Its Drug Resistance. Front Cell Infect Microbiol 2022, 12, 926758, doi:10.3389/fcimb.2022.926758

[10] Pinna, A.; Usai, D.; Sechi, L.A.; Molicotti, P.; Zanetti, S.; Carta, A. Detection of Virulence Factors in Pseudomonas Aeruginosa Strains Isolated From Contact Lens-Associated Corneal Ulcers. Cornea 2008, 27, 320–326, doi:10.1097/ICO.0b013e31815c5a3f.

Line 51-52, relevant reference(s) is needed here for the introduction of pyocyanin.

We have added the reference:

[14] Gonçalves, T.; Vasconcelos, U. Colour Me Blue: The History and the Biotechnological Potential of Pyocyanin. Molecules 2021, 26, 927, doi:10.3390/molecules26040927.

Line 73-74, I suggest the authors addressing why they collected throat, naris and outer ear swab samples, not the others here. 

We have added the reasons:

“These areas were chosen for sample collection because of their humidity and sampling convenience with less discomfort for the participants”.

Line 82, “oprL” italic

We have revised it.

Line 124, “In case of siderophores” not italic

We have revised it.

Line 147-150, relevant reference(s) is needed here for the introduction of oprL.

We have added the references:

[22] De Vos, D.; Lim, A.; Pirnay, J.P.; Struelens, M.; Vandenvelde, C.; Duinslaeger, L.; Vanderkelen, A.; Cornelis, P. Direct Detection and Identification of Pseudomonas Aeruginosa in Clinical Samples Such as Skin Biopsy Specimens and Expectorations by Multiplex PCR Based on Two Outer Membrane Lipoprotein Genes, OprI and OprL. J Clin Microbiol 1997, 35, 1295–1299.

[32] Matthijs, S.; Coorevits, A.; Gebrekidan, T.T.; Tricot, C.; Wauven, C.V.; Pirnay, J.-P.; De Vos, P.; Cornelis, P. Evaluation of OprI and OprL Genes as Molecular Markers for the Genus Pseudomonas and Their Use in Studying the Biodiversity of a Small Belgian River. Research in Microbiology 2013, 164, 254–261, doi:10.1016/j.resmic.2012.12.001.

[33] Abdullahi, R.; Lihan, S.; Carlos, B.; Maurice Bilung, L.; Michelle, K.; Collick, F. Detection of OprL Gene and Antibiotic Resistance of Pseudomonas Aeruginosa from Aquaculture Environment. European Journal of Experimental Biology 2248-9215 2013, 3, 148–152.

Line 165-169, could the authors discuss why the throat was primarily colonized by P. aeruginosa here?

We have added the discussion as followed:

“It was consistent with previous studies in which P. aeruginosa is likely found in mucoid and humid area and is the most common Pseudomonas causing infection in human [39,40]” (line 176-178)

In Table 3, it seems that biofilm of commensal P. aeruginosa isolates has a big difference from P. aeruginosa ATCC 9027, while the other virulence factors are quite similar between commensal P. aeruginosa isolates and P. aeruginosa ATCC 9027. Could the authors give some explanations?

The explanation is now added as below:

 “In addition, the biofilm production of commensal P. aeruginosa isolates was weaker than the P. aeruginosa ATCC 9027 (positive control). Some studies showed less dominance of strong biofilm producers in the clinical isolates [50] and isolates from cystic fibrosis patients [51]. Biofilm production did not associate with poor clinical outcomes [52]. Moreover, it was reported that P. aeruginosa often grew planktonically and did not form biofilm under laboratory conditions [53].” (line 285-291)

In Fig1C, it’s a little confusing for C2, because nothing is observed here. 

The explanation is now added as below:

“HDTMA in CAS agar was toxic to Gram-positive bacteria, so S. aureus was inhibited and did not grow at C2 position” (Figure 1)

Reviewer 3 Report

The manuscript "Prevalence and virulence of commensal Pseudomonas aeru- 2 ginosa isolates from healthy individuals in Southern Vietnam 3 (2018-2020) " is based on a pressing problem, Pseudomonas infection. I think care was not taken to write the manuscript. Numerous typos and mistakes are in the manuscript. Please see some of the highlighted typos and mistakes in the attached file.

Comments for author File: Comments.pdf

Author Response

Dear Reviewers

Thank you for your comments. We would like to submit the revised version of the manuscript entitled “Prevalence and virulence of commensal Pseudomonas aeruginosa isolates from healthy individuals in Southern Vietnam (2018-2020)”. The edit tracking was turned on, and the edited parts were highlighted in the revised manuscript.

Below is our response to your specific comments.

The manuscript "Prevalence and virulence of commensal Pseudomonas aeru- 2 ginosa isolates from healthy individuals in Southern Vietnam 3 (2018-2020) " is based on a pressing problem, Pseudomonas infection. I think care was not taken to write the manuscript. Numerous typos and mistakes are in the manuscript. Please see some of the highlighted typos and mistakes in the attached file.

We have corrected the English typo, spaces, captions, dots, units, and commas in both the manuscript and the supplementary file. Thank you very much!

Round 2

Reviewer 1 Report

This paper is revised according to reviewer's suggestions.

This paper should be accepted. 

Reviewer 3 Report

Reviewers have addressed my concerns. I recommend the manuscript for publication.