Beta-Lactam Susceptibility Profiles of Bacteria Isolated from the Ozama River in Santo Domingo, Dominican Republic

Round 1

Reviewer 1 Report

The authors presented a study on bacteria profiles from Ozama River in Dominican Republic. It's an interesting topic that help the audience understand the importance of monitoring wastewater discharge, as the analysis of multi-resistance genomes showed the a variety of bacteria are present which affect water health. The paper has some merit with extensive physical, chemical, and biological characteristics. However, there is not much mention in terms of novelty of this research, which is a very important aspect of being considered for publication. In order for this study be considered for publication, a direct comparison to published papers must be made to discuss the novelty. 

Author Response

Author response: Thank you for pointing this out. The reviewer is correct, and we have reformulated our discussion to provide further visibility to the study's novelty. Please review the discussion section.

Author response: Thank you for pointing this out. The reviewer is correct, and we have reformulated our discussion to provide further visibility to the study's novelty. Please review the discussion section.

Reviewer 2 Report

The manuscript entitled „Beta-lactam susceptibility profiles of bacteria isolated from the Ozama River in Santo Domingo, Dominican Republic” by Roberto Bonnelly et al. raises the fundamental issue of the prevalence of antibiotic-resistant bacteria and the relationship of drug resistance to anthropogenic factors. The Authors studied water taken from three sites from the Ozama River in Santo Domingo, Dominican Republic. The authors identified bacterial species resistant to beta-lactams, including those showing multidrug resistance. These results highlight a serious problem posed by the irresponsible use of antibiotics, particularly in urban areas. Immediate steps should be taken to counter this phenomenon, such as limiting the over-the-counter availability of antibiotics.

This article is well written. The obtained results are adequately described, but I think they should be better discussed following the current literature.

Comments:

1.       There is too much information about the Ozama River in the introduction. Paragraphs from line 48 to 97 should be summarised to a maximum of 3-4 sentences (one paragraph). The rest of the information, which by the way is interesting, should be moved to the discussion and serve as justification for the results obtained.

2.       Lines 117-118: M&M section: The Authors state that three samples were collected from each site in June 2019. At what intervals were samples collected? Were the samples collected at one time? Were the “triplicates” considered technical or biological repetitions?

3.       Line 122: There is a lack of time specification. I suppose it should be six hours.

4.       Line 126: The reference should be added.

5.       Line 140: Surely not 1L. 1 microlitre?

6.       Line 164: It would be good to specify in the text what country these requirements are (Dominican Republic?).

7.       Table 1. Explain in the legend what A, B and C stand for.

8.       Figures 3 and 4. Add explanations of abbreviations.

9.       Line 285: Please, rephrase the first sentence. How much? 10 out of 23?

10.   Discussion section: There is a lack of references to other studies also conducted in other agglomerations.

11.   Lines 395-396: Are the statistics of antibiotic intake in Santo Domingo known? They are certainly higher than in countries where antibiotics are prescribed. It would be helpful to refer to antibiotic resistance studies of bacteria conducted in places where prescriptions are required, and antibiotic intake (including in animal farms) is more strictly controlled.

12.   In the discussion, it would be worthwhile to depict the consequences of drug resistance and propose preventive solutions.

13.   Conclusion section, lines 444-446: Discuss potential causes (and move to the Discussion section).

Author Response

Comments:  1.       There is too much information about the Ozama River in the introduction. Paragraphs from line 48 to 97 should be summarised to a maximum of 3-4 sentences (one paragraph). The rest of the information, which by the way is interesting, should be moved to the discussion and serve as justification for the results obtained. 

Author response: Thank you for pointing this out. The reviewer is correct, and we have reduced the paragraph and the description of the river and kept the essential information so that the context of the river can be understood within the investigation. Please see in the introduction section lines 40-59.

 Comments:  2.       Lines 117-118: M&M section: The Authors state that three samples were collected from each site in June 2019. At what intervals were samples collected? Were the samples collected at one time? Were the “triplicates” considered technical or biological repetitions? 

Author response: Thank you for pointing this out. The reviewer is correct, and We have better explained the process of collecting water samples in the methodology section. Please see lines 76 to 89.

 Comments:  3.       Line 122: There is a lack of time specification. I suppose it should be six hours.

Author response: Thank you for pointing this out. We have corrected the collected samples' processing time, which has been corrected on line 89.

  Comments: 4.       Line 126: The reference should be added. 

Author response: We have added the suggested content to the manuscript on line 94.

  Comments: 5.       Line 140: Surely not 1L. 1 microlitre?  
 Author response: Thank you for pointing this out. We have changed the unit to the correct one. Please check line 112.

  Comments:  6.       Line 164: It would be good to specify in the text what country these requirements are (Dominican Republic?). 

 Author response: Thank you for pointing this out. We have specified the country of the regulations so that the text is more precise. Please see line 144

   Comments: 7.       Table 1. Explain in the legend what A, B and C stand for. 

 Author response: Thank you for pointing this out.We have improved the table and explained the legends so the reader can interpret them. Please see table 1

   Comments: 8.       Figures 3 and 4. Add explanations of abbreviations. 

Author response: As suggested by the reviewer, we have removed figure 3 and referenced the abbreviation of figure 4. Please see figure 4

   Comments:  9.       Line 285: Please, rephrase the first sentence. How much? 10 out of 23?  
Author response: Thank you for this suggestion. We have reformulated the sentence to make the result clearer to the reader. Please see line 253

  Comments: 10.   Discussion section: There is a lack of references to other studies also conducted in other agglomerations. 

Author response: Thank you for this suggestion. We have enriched our discussion with studies from other places. Please check the discussion section

   Comments: 11.   Lines 395-396: Are the statistics of antibiotic intake in Santo Domingo known? They are certainly higher than in countries where antibiotics are prescribed. It would be helpful to refer to antibiotic resistance studies of bacteria conducted in places where prescriptions are required, and antibiotic intake (including in animal farms) is more strictly controlled. 

 Author response: We have yet to find any official statistics for the Dominican Republic, but a few comparisons were made to a study made in the US. Thanks for pointing it out.

  Comments:  12.   In the discussion, it would be worthwhile to depict the consequences of drug resistance and propose preventive solutions.  

Author response: Thank you for this suggestion. We have enriched our discussion with studies from other places. Please check the discussion section.

  Comments:  13.   Conclusion section, lines 444-446: Discuss potential causes (and move to the Discussion section).

Author response: Thank you for this suggestion. We have enriched our discussion with studies from other places. Please check the discussion section

 

Reviewer 3 Report

Dear Authors,

 

Thank you for your manuscript submission “Beta-lactam susceptibility profiles of bacteria isolated from the Ozama River in Santo Domingo, Dominican Republic.” The manuscript showed the abundance of antimicrobial-resistant bacteria in surface water in Ozama river, which potentially influences human health. Here are my specific comments:

-          Line 85-88, reference(s) is required for the numbers.

-          What is the innovation and significance of this study compared with previous studies? More details are required

-          Figure 1 should be inserted below line 113, which will help readers to easily follow the main content of the study.

-          Line 125, reference detail for the book "Standard 125 Methods for the Examination of Water and Wastewater" should be provided in the reference list. More details on the instruments to measure pH, COD, BOD, DO, turbidity, total P and N should be provided.

-          Are any equations or assumptions required for the calculation?

-          Line 223-244, there paragraphs should be put in the materials and methods as they are not results.

-          Figure 3, axis title is missing

-          Line 294, are there any reasons why the highest level of resistance to multiple antibiotics is at Point 2?

-          Are there any limitations for the method in this study?

-          More details for future research are required

-          Some references in the references list are in Spanish, which make them hard to be found if someone would like to check or use the details in those references. Using new references or translating them into English should be considered.

-          Many references have been superseded, such as ref 23, ref 4, ref 13, ref 29, etc. More updated references are required.

Author Response

 

Comment 1:  Line 85-88, reference(s) is required for the numbers.

Author response: Thank you for pointing this out. According to the recommendations of another reviewer, we have reduced the text related to the river and added the references. Please check the introduction section.

 

Comment 2: What is the innovation and significance of this study compared with previous studies? More details are required

Author response: Thank you for pointing this out. We have reformulated the discussion section, highlighting this study's innovation.

 

 Comment 3:  Figure 1 should be inserted below line 113, which will help readers to easily follow the main content of the study.

 

Author response: As suggested by the reviewer, We have changed the position of figure 1 to make it easier to read. We have also modified it so that the points within the country map can be viewed at the request of another reviewer. Please check figure 1

 

  Comment 4 : Line 125, reference detail for the book "Standard 125 Methods for the Examination of Water and Wastewater" should be provided in the reference list. More details on the instruments to measure pH, COD, BOD, DO, turbidity, total P and N should be provided. Done

 

Author response: As suggested by the reviewer, We have added the book to the bibliography. We have also added details about the instruments and methods used to measure the physical-chemical parameters.

 

Comment 5 :Are any equations or assumptions required for the calculation?

 

Author response:Thank you very much for pointing this point out. We have added the details to the text. The tests were carried out in an external laboratory.

 

 Comment 6: Line 223-244, there paragraphs should be put in the materials and methods as they are not results. Figure 3, axis title is missing 

 

Author response:Thank you very much for pointing this point out. We organized the paragraphs and moved them to the corresponding section. In addition, figure 3 was removed at the request of another reviewer, and in figure 4, we have clarified the abbreviations.

 

 Comment 7: Line 294, are there any reasons why the highest level of resistance to multiple antibiotics is at Point 2? 

Author response: Thanks for the question. Yes, this point is located in the river delta, where you have already made a tour of the city and received the discharge of a large amount of informal drainage. In addition, it receives water from the Isabela River, which has high levels of contamination due to anthropic action.

 

  Comment 8: Are there any limitations for the method in this study? 

Author response:  Thanks for the question. Yes, the MALDI-TOF database, it was now added into the paper.

 

  Comment 9:    More details for future research are required. 

Author response: Thank you very much for pointing this point out. We have rewritten much of the text to make it more precise for future research.

 

 

   Comment 10:  Some references in the references list are in Spanish, which make them hard to be found if someone would like to check or use the details in those references. Using new references or translating them into English should be considered. 

 

Author response:  Thank you for your suggestion, but due to the limited bibliography on the subject in the region, these references are necessary. We put it in the original language (Spanish) so that it can be found more easily and quickly by readers who want to consult them.

 

    Comment 11:   Many references have been superseded, such as ref 23, ref 4, ref 13, ref 29, etc. More updated references are required.

Author response: Thanks for the suggestion. We have updated some references, but many are necessary to contextualize the work to the country. We are a pioneer in this type of genomic study in the Dominican Republic. There needs to be more-published literature on similar works in the country.

Reviewer 4 Report

I have outlined below my understanding and thoughts on it, in the hopes, they will help in further improving its scientific contribution
(1) In the abstract:

-          MALDI-ToF- Write the full name.

 

(2) In the Materials and Methods section:

 

-          Figure 1 there must be a bar showing distances. Add to Fig. 1 a bar showing 100 or 10 km (see this paper for your reference https://doi.org/10.3390/w14203297 )

-          BD Phoenix ID broth and AST – wire the full name for all abbreviations in the methodology section when it writes for the first time).

 

 (3): In the results:

-          Better to change the abbreviation biological oxygen demand – BOD and chemical oxygen demand - COD

(4): In the conclusion section:

-          No need for references- the conclusion just summarizes the mean results of the study. The references should move to the discussion section.

 

 

 

Author Response

 

 Comment 1: M(1) In the abstract: MALDI-ToF- Write the full name.

Author response: As suggested by the reviewer, We have added the full name of the method in the abstract. 

 

Comment 2: In figure 1, there must be a bar showing distances. Add to Fig. 1 a bar showing 100 or 10 km (see this paper for your reference https://doi.org/10.3390/w14203297 )

Author response: As suggested by the reviewer, We have modified figure 1 so that the points can be visualized on the map and better understood by readers. Please review figure 1.

 

Comment 3: BD Phoenix ID broth and AST – wire the full name for all abbreviations in the methodology section when it writes for the first time). 

 

Author response: While we appreciate the reviewer’s feedback, we respectfully disagree because these are the full names of these teams and by which the scientific community knows them.

 

Comment 4:Better to change the abbreviation biological oxygen demand – BOD and chemical oxygen demand – COD 

 

Author response: This is an excellent suggestion. We have changed the nomenclature. Thanks for the suggestion.

Comment 4: No need for references- the conclusion just summarizes the mean results of the study. The references should move to the discussion section.

Author response: This is an excellent suggestion. We have received the references, and we have written the discussion section.

Round 2

Reviewer 1 Report

The authors have made improvement based on the first revision that background information about Santa Domingo and significance of this study using MALDI-TOF is provided, which can be more interesting for the audience. Data are clearly presented in tables and figures. Therefore, I would recommend publication of this research. 

Reviewer 2 Report

The Authors have significantly improved the manuscript. I have no further comments.