Prevalence and Antimicrobial Susceptibility Patterns of Wound and Pus Bacterial Pathogens at a Tertiary Care Hospital in Central Riyadh, Saudi Arabia

1. Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files

2. Questions for General Evaluation

Reviewer’s Evaluation

Response and Revisions

Does the introduction provide sufficient background and include all relevant references?

Must be improved

We thank the reviewer for pointing this out. We have revised (line 36-38, 45-63, 65-67, 71-75, 78-81, 86-92)

Are all the cited references relevant to the research?

Yes

Is the research design appropriate?

Yes

Are the methods adequately described?

Yes

Are the results clearly presented?

Yes

Are the conclusions supported by the results?

Yes

3. Point-by-point response to Comments and Suggestions for Authors

 Comments 1:   It is not emphasized how the data tells us something that has not been reported before.  Of course, all infectious disease physicians know the importance of monitoring antibiotic choices for prophylaxis and treatment in the study area. Tell us something new about the data that was not reported before (other than the location)

Response 1: We agree with the reviewer that further elaboration on this point is needed. Thank you for pointing this out.

To our knowledge this is the first study from the region reporting all wound infections cases together and giving overall picture of these infection with detailed statistical analysis. Previous studies are focusing on surgical site wounds or burns cases and many other surveys are reported on specific bacteria (MRSA, VRE, Pseudomonas etc). This research initiative aimed at shedding light on the epidemiology of antimicrobial resistance by focusing on the dynamic interplay between bacterial pathogens and antimicrobial agents, particularly in the context of wound infections, among individuals seeking medical attention at the specified healthcare facility. By conducting a detailed analysis of the antimicrobial susceptibility patterns observed in both in- and outpatients, the study sought to contribute valuable insights that could inform future treatment strategies, enhance antimicrobial stewardship practices, and ultimately improve patient outcomes and public health interventions. (page 17, line 330-334)

Comments 2: Tables 2 and 3 are well constructed and thorough, with acceptable statistical methods, but they are missing the Streptococcus species and many anaerobic bacteria, as pointed out in the discussion as a limitation. However, there are many other interesting findings with what the authors did report

Response 2: Thank you for your feedback.

We could not include Streptococci and anaerobic bacterial isolates in our study as it was a retrospective study design and from the lab record we were not able to retrieve this data from the antibiogram. For streptococcal isolates mostly they are released with the lab note that this isolate is usually sensitive to penicillin and ampicillin, hence excluded from antibiogram. Anaerobic bacterial isolates are also released with the comment that this isolate is sensitive to metronidazole and no other antimicrobial agents were tested in our hospital facility. However, for future studies, we will keep this point and maintain a record of these isolates as well.

Comments 3: The sex and age differences in resistance to certain drugs (Tables 6 and 7) are the most interesting pieces of data and this should be emphasized more.

Response 3: We agree and have updated

(Page 16, line 318-322, page 17, line 330-334)

Comments 4:  The location of the wound and more hospital data should be reported to give us an idea of where bacteria species such as E. coli came from in a wound.

Response 4: We appreciate the reviewer’s insightful suggestion and agree that it would be useful to demonstrate this detail; however, this is our study limitation as it was a retrospective study so could not follow up on the patient history of bloodstream infections or other culture positive for bacterial growth before developing wound infections.

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files

Comments 1:   My main concern is: why did the authors perform this work? What is the scientific motivation? The authors cite several papers on the same subject, many of them from Saudi Arabia  (as in this manuscript). So, why repeat these studies?

Response 1: Thank you for your comment.

To our knowledge this is the first study from the region reporting all wound infections cases together and giving overall picture of these infection with detailed statistical analysis. Previous studies are focusing on surgical site wounds or burns cases and many other surveys are reported on specific bacteria (MRSA, VRE, Pseudomonas etc). Most of the previously reported studies are conducted for a short period of time without specifying the site of wound infections. This research initiative aimed at shedding light on the epidemiology of antimicrobial resistance by focusing on the dynamic interplay between bacterial pathogens and antimicrobial agents, particularly in the context of wound infections, among individuals seeking medical attention at the specified healthcare facility. By conducting a detailed analysis of the antimicrobial susceptibility patterns observed in both in- and outpatients, the study sought to contribute valuable insights that could inform future treatment strategies, enhance antimicrobial stewardship practices, and ultimately improve patient outcomes and public health interventions. (page 17, line 330-334)

Comments 2: I have another major comment: the authors did not “measure” anaerobes. Therefore, perhaps the percentages appearing in the manuscript are not correct. These are percentages among culturable aerobic bacteria. Therefore, it is hard to compare their results with the ones obtained in the other papers (mainly in the Discussion section).

 Response 2: We appreciate the reviewer’s insightful suggestion and agree that it would be useful to demonstrate this detail; however,

We could not include anaerobic bacterial isolates in our study as it was a retrospective study design and from the lab record we were not able to retrieve this data from antibiogram. Anaerobic bacterial isolates are released with the comment that this isolate is sensitive to metronidazole and no other antimicrobial agents were tested in our hospital facility. Nevertheless, we mention this point in the discussion section as our study limitation. However, for future studies we will keep this point and maintain a record of these isolates as well.

Comments 3: All figures: please do NOT use 3D graphics. 2D graphics are much easier to read (easier to extract information)

Response 3: We agree and have updated

(Page 4, line 155, page 5, line 167, page 6, line 174, page 7, line 186, 193)

Comments 4:  Line 22: define XDR

Response 4: We thank the reviewer for pointing this out. We have revised

(Page 1, line 22-23)

Comments 5:  Lines 52-54: in what way does your work (this manuscript) contribute to combat resistance, improving patient care, etc?

Response 5: We thank the reviewer for pointing this out.

This is general practice in our hospital to start the treatment with broad spectrum antibiotics without knowing the causative pathogen. By this report we are able to know that no Pan drug resistant organism was isolated from our setting. Although extensive drug resistant (XDR) bacterial isolates are reported but their percentage is very less (6.3%). And for this minor percentage of resistant organisms, it is not advisable to treat the reaming 94% cases with broad spectrum antibiotics. Mostly we need to hospitalize the patient as these chosen broad spectrum antibiotics are injectable like carbapenems. This work is our humble attempt to stop this practice of misusing the resort antibiotics in order to save them for life threatening situations and to avoid the unnecessary exposure of broad spectrum antibiotics to the patients and to the bacteria in order to avoid resistance development.  

Comments 6: Lines 54-58: these two sentences are displaced. Should be slightly above

Response 6: We thank the reviewer. We have revised

(Page 2, line 78-81)

Comments 7: Lines 129-130: which statistical test did the authors use? How many degrees of freedom?

Response 7: As we received conflicting advice from another reviewer, we decided to remove this table and data set from our manuscript. We hope this was the right decision.

Comments 8: Table 3: take care with formatting of the Table

Response 8: As we received conflicting advice from another reviewer, we decided to remove this table from our manuscript.

Comments 9: Figures 2 and 3: the order of antibiotics should be the same.

 Response 9: We thank the reviewer. We have revised

(Page 5, line 167, page 6, line 174)

Comments 10: Tables 4, 5, 6, 7, and 8: Please consider using Bonferroni correction in each Table. Why?  Consider, for example, Table 4 alone. You are testing 13 antibiotics to check if there are differences between males and females. You used alpha=0.05. However, by performing 13 Student t-tests, you are expected to see differences between males and females (regarding antibiotic resistance) just by chance. That is, by performing many tests in a row, the probability of observing a rare event increases, and therefore, the likelihood of incorrectly rejecting a null hypothesis (i.e., making a Type I error) increases. You tested 13 times, so you should use alpha = 0.05/13 = 0.0039. Therefore, the t-test is significant is p<0.0039 only (for Table 4).

Response 10: We appreciate the reviewer’s insightful suggestion and agree that it would be useful to use Bonferroni correction for these tables and changes has been made as recommended by the reviewer.

(Page 8, line 204, page 9, 10, line 212, page 10, 11, line 219, page 11, 12, 13, line 226, page 13, 14, 15, line 236)

Comments 11: Lines 205-210. I did not understand the percentages of mono and poly. In line 205 one can read 53% of monomicrobial infections. Does that mean 100%-53% = 47% polymicrobial infections? So why the numbers 9.4% and 2.5% in line 209?

Response 11: We apologize if our statement was not conveying our message. We have modified the statement and hope that it is now clear that 47% were polymicrobial infections and 53% were monomicrobial. We compare our results to Alharbi and Maharjan et al who reported 9.4% and 2.5% polymicrobial wound infections in their studies respectively.

(Page 15, line 255-256)

Comments 12: delete “Our results revealed that” to avoid repetition with the previous paragraph.

 Response 12: deleted as suggested

(Page 16, line 270)

Comments 13: There is something wrong with the sentence “Penicillin had the highest resistance to Staphylococci,…”!

Response 13: Thank you for highlighting. We revised the statement

(Page 16, line 279)

Comments 14: Line 251: Please define CRE

Response 14: Thank you for the mention. We defined

(Page 16, line 302)

We would like to thank you again for taking the time to review our manuscript

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files

Comments 1:   The title needs to be changed. The fact that this paper deals with wound and pus cultures is more important to be pointed out rather than listing the fact that these are aerobic microorganisms, or that the patients were in- and out-. It is nice to point out the geographical location, as this is often interesting to readers. Please, make the changes in order to make your paper more visible for potential readers.

Response 1: Thank you for your comment. We agree with the recommended changes and revised our title

(page 1, line 2-4)

Comments 2: Introduction is fine, I especially like the fact that it is brief. However, it would be nice to add anything about pus, and its correlation to wounds, infections, any data at all, as currently it has none.

 Response 2: We appreciate the reviewer’s insightful suggestion and agree that it would be useful to demonstrate this detail and revised our introduction section

(page 1, line 36-38, page 2, line 46-63)

Comments 3: Figure 1- please explain what other wounds include. Also, please make distinction from others as in pathogens that were isolated from wounds.

Response 3: We agree and have updated the figure according to valuable suggestion by the reviewer

(Page 4, line 155-157)

 Comments 4:  The results start nicely, however- lines 126-130 and table 3 should be removed. There is no logical explanation why should gender correlate with isolated microorganism! I could find logic in correlating e.g. microorganism in urinary tract infection, as there are anatomical and microbiota differences between sexes which could affect causative agent of infection, however- just because you can find a statistical number in one test, does not mean that you should. Statistics is a powerful tool but it should be used with logic. Yes, you will find a data in literature that women are more frequently infected in these or those cases, but that does not mean that this relationship is causative. So, a sincere advice to Authors- remove this part of manuscript!

Response 4: We appreciate the reviewer’s insightful suggestion and agree that it would be better to remove table 3 and this part of data set from our manuscript.

(removed from the manuscript)

Comments 5:  Everything previously said goes also for 3.5. Antimicrobial Resistance Profile Correlation with Gender. I will also point out that you really should not make conclusions based on such small numbers e.g. ampicillin in table 4. This part of manuscript should also be removed.

Response 5: As we received conflicting advice from another reviewer, we decided to make the change they suggested. To use Bonferroni correction for these tables is recommended to report such data. For example, Table 3 alone. We are testing 13 antibiotics to check if there are differences between males and females. We used alpha=0.05. However, by performing 13 Student t-tests, we are expected to see differences between males and females (regarding antibiotic resistance) just by chance. That is, by performing many tests in a row, the probability of observing a rare event increases, and therefore, the likelihood of incorrectly rejecting a null hypothesis (i.e., making a Type I error) increases. We tested 13 times, so we should use alpha = 0.05/13 = 0.0039. Therefore, the t-test is significant is p<0.0039 only (for Table 3). We hope this was the right decision.

(Page 8, line 204, page 9, 10, line 212, page 10, 11, line 219, page 11, 12, 13, line 226, page 13, 14, 15, line 236)

Comments 6: Regarding the two following chapters, 3.6 and 3.7, I could find a logic in correlating resistance profile with patient settings and age, however, I believe that the results would be sufficient even without correlation- a simple descriptive statistics is sometimes just fine and enough.

Response 6: We appreciate the reviewer’s insightful suggestion and agree that it would be better to use only descriptive statistics; however, as we received conflicting advice from other reviewers, we decided to make the change they suggested. We hope this was the right decision

Comments 7: Section 3.8-Is table 9 missing?

Response 7: This observation is correct. Thank you for pointing out. We have updated

(Page 15, line 244)

Comments 8: My general advice to Authors- remove the excessive part and your paper will be just fine. You should not try to make it "more" than it is, it is and will be more than enough.

Response 8: We appreciate the reviewer’s insightful suggestion and agree that it would be better to remove excessive part from our manuscript and changes has been made.

We would like to thank you again for taking the time to review our manuscript