New Insights into Molecular Characterization, Antimicrobial Resistance and Virulence Factors of Methicillin-Sensitive Coagulase-Positive Staphylococcus spp. from Dogs with Pyoderma and Otitis Externa

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 

In the manuscript entitled "New insights into molecular characterization, antimicrobial resistance and virulence factors of methicillin sensitive coagulase positive Staphylococcus spp. from dogs with pyoderma and otitis externa", the authors present microbiological analyses of samples from dogs with dermatological infections in Tunisia.  The topic is interesting and important to study; but the manuscript is not written clearly, and the study lacks any obvious controls.  Therefore, I cannot recommend this manuscript for publication.  Some items that must be addressed are as follows:

1.     Please use an English editing service.

a.     Many verbs are misused either in definition or in conjugation.  For example, the sentiment in the last sentence of the abstract is not clear due to the incorrect vocabulary usage.

b.     The text is written very informally, and formal English syntax should be used in this type of document.

 

2.     Be sure to define all abbreviations prior to their first use in the manuscript.

a.     In particular, the abbreviations MLST and ST are not defined until page 4.

b.     Abbreviations should be avoided in section headings.  (e.g., Section 3.7 title)

 

3.     The Methods section is incomplete.

a.     All materials should be cited not just to company of purchase, but also to the city/country of manufacture.

b.     The process of PCR was never described.  The process of DNA sequencing was never described or cited, as applicable.

c.      The methods section should allow your reader to repeat the process you used.  Therefore, additional details about that process must be provided.  For example, in 2.7 on the Biofilm Assay, when the plates “were further washed again” – with what solution?  (To return to a previous point, “further” and “again” are redundant, providing an illustration of incorrect English syntax.)

 

4.     Tables and Figures are not formatted correctly.

a.     Tables 2 and 3 are completely unintelligible – at least in the version that this reviewer received.

b.     The Figure legends are incomplete.  No descriptions are included.  In addition to the figure title, the figure should be described, the methods used should be stated, and any symbols/colors/abbreviations should be defined.

c.      Part of the Figure 1 Legend is missing.

 

5.     The Results section is quite thorough, but the authors are encouraged to review it so as to ensure that all content is appropriately written for that section.  Some of the results trended more to interpretations (should be in Discussion) than true observations (as would belong in the Results).

 

6.     The Discussion section is shaping up nicely, but still needs substantial work.

 a.     The rationale for experimentation is appreciated.  Repeating these reasons sooner in the Results section would be greatly appreciated by future readers.

b.     The authors are encouraged to break the discussion into logical sections to help readers follow the logic presented.  Right now, the discussion is just a list of seemingly random thoughts.

c.      Most importantly, this study does not include an experimental control.  Therefore, the conclusions do not follow from the data presented.  At the end of the Introduction, the authors state that their study contributes insights into the “epidemiology” of such canine Staph infections, but epidemiological methods are not employed.

The authors mention previous studies of healthy dogs.  Are these two publications intended to be the control population?  If so, the data needs to be presented as such.  Further, the referenced publications are almost ten years old, so are their findings still relevant to the current environment?  At a minimum, the authors need to confirm/update any trends established in the aforementioned publications.

 

This work has the potential to become a significant contribution.  Please clearly express the big picture for the topic and perform the appropriate controls prior to resubmitting this study for publication.

 

Comments on the Quality of English Language

Please use an English editing service.  Your message is often lost in translation.  Formal English syntax needs to be used consistently.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

New insights into molecular characterization, antimicrobial resistance and virulence factors of methicillin sensitive coagulase positive Staphylococcus spp. from dogs with pyoderma and otitis externa.

 

Abstract:

The abstract is written and detailed.

Keywords: I suggest that you replace the words that already appear in the title of the manuscript.

Introduction

In the section “...Currently, CoPS group includes ten species: S. aureus, S. intermedius, S. pseudintermedius, S. coagulans (previously known as S. schleiferi subsp. coagulans), S. hyicus (variable coagulase), S. delphini, S. lutrae, S. agnetis (variable coagulase), S. cornubiensis and S. ursi [4-6]. S. intermedius, S. pseudintermedius, S. delphini, S. cornubiensis and S. ursi belongs to the S. intermedius group (SIG group)” - In the first species in the group I suggest you write the genus in full, and in the others you can simplify the genus.

 

Materials and Methods

Were these samples not approved by the animal ethics committee?

Discussion

The ellipsis at the end of this paragraph indicates a thought that has not yet been completed or the omission of something that has not been written. “Pyoderma (or skin infections) and otitis externa are main aspects in the clinical practice in dogs. These infections are caused predominantly by staphyloccocal coagulase positive strains, represented mainly by S. pseudintermedius known as common colonizer and opportunistic pathogen of animal skin and mucosal cavities, followed by other species including S. cogulans, S. aureus…” Can the authors provide the reason for the ellipsis at the end of the paragraph? Was any information missing?

Conclusions

This topic needs to be rewritten, as it does not reflect the importance of the study, the way it was written seems like a presentation of results.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

In the work of Faten Ben Chehida et al, pyoderma and otitis externa were studied, which are the main aspects of clinical practice in dogs. These infections are caused mainly by staphylococcal coagulase-positive strains, represented mainly by S. pseudintermedius, known as a common colonizer and opportunistic pathogen of the skin and mucous membranes of animals, followed by other species. The article defines antimicrobial resistance profiles and analyzes the molecular structure of the detected isolates. It should be noted that in the current study, double and triple infection with several species of the same animal was noted. The mechanism of antagonism between S. aureus and S. pseudintermedius is suggested. These articles indicate the appearance in Tunisia of S. hyicus, multidrug-resistant pathogens S. pseudintermedius and S. aureus with pronounced STS in sick dogs.

The article found a negative relationship between resistance and virulence, mainly among strains of S. aureus and S. pseudintermedius. In particular, S. pseudintermedius strains contain a large set of antibiotic resistance genes, while S. aureus strains contain a wide range of virulence genes.

The presence of genes responsible for capsule formation and adhesion in isolates was established, and one isolate carried multiple capsule types. This is very interesting information.

Tests were carried out with polystyrene and it turned out that 75% of S. aureus isolates adhered to the surfaces, of which 15% were classified as strong biofilm producers. The genotype of capsular polysaccharide cap8 prevailed among them.

 

Considering the above, the results indicate the spread of CoPS among diseased dogs, namely the appearance of S. hyicus and S. coagulans, S. pseudintermedius with multidrug resistance and S. aureus with high genetic variability. And this negatively affects the possibility of zoonotic infections. Therefore, the article is important not only for veterinary medicine, but also for human microbiology.

 

Table 2 – Cell offset, needs to be corrected, cannot be read.

 

Statistical deviations should be added to the diagrams

 

The article can be printed with minor edits.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

 

In this revision of the manuscript entitled "New insights into molecular characterization, antimicrobial resistance and virulence factors of methicillin sensitive coagulase positive Staphylococcus spp. from dogs with pyoderma and otitis externa", the authors have made some positive improvements over the previous version of the manuscript by adding important details and improving the clarity of the text.

As with any document, proofreading is never complete.  The following are minor editing points that the authors will wish to address prior to publication:

1.  Regarding the Supplemental Table

·       Please be consistent referencing it in the main text.

·       PCR amplicon size units are not indicated in the table.

2.     Regarding the main text tables

·       The labeling is incorrect in Table 1.  The heading says percent (number), but the data looks to be given as number (percent).

·       In Table 3, the abbreviations ST/CC are not defined in the footnotes.

3.     Figure legends still are not formatting correctly.

4.     Miscellaneous line item problems

·       Line 122 – What is the abbreviation “dest.”?

·       Lines 74-175 – If S. intermedius and S. delphiniare not present in Table 1, the citation should be moved to the previous sentence.

·       Line 183 – 15 of 39 dogs would mean 38.46%, not the 39.47% stated.

·       Line 439 – the conclusion stated is that of the citation, not the authors, correct?  If so, please re-word to indicate that fact.

·       Line 450 – “Proven” is not the correct word to use.  Remember, in science, the best we can hope to do is repeatedly fail to disprove…

·       Lines 452-455 – Be consistent with the Roman and Greek letters, as applicable.

·       Line 462 – Spot-checking the references, I noticed that Ref. 79 is a review.  If you wish to cite specific data from that review, the original primary literature should cited either instead of or in addition to the review.

 

Unfortunately, I again cannot recommend this manuscript for publication at this time given that experimental rigor still is lacking in the work presented.

1.     All PCR results require more explanation

·       Were reactions performed in replicate or only once?

·       To demonstrate negative results, a positive control is needed.  Presenting the raw results of the PCRs (or at least a representative sample thereof) would go a long way towards allowing your readers to accurately assess your work.

2.     Results are difficult to understand

·       For example, Figure 1 - What is meant by prevalence on the y-axis?  How can the prevalence be >100%?  Legend incorrectly formatted and incomplete.  No method stated in either Figure legend or in main text.

·       Percentage calculations would benefit from more explanation.  More transparency in the calculations would help to demonstrate that you are presenting unbiased data rather than finessing the numbers to prove your point.

3.     Other line item problems

·       Lines 180-181 – What “frequencies” are referenced here?  Were statistics performed to demonstrate the difference between them?

·       Lines 183-186 – As the manuscript stands now, no evidence is provided for the claims of multiple infections.  Presenting your data more explicitly should fix this oversight.

·       Line 195 – Exactly what is meant by “>3% resistance”?

·       Line 492 – What is meant by a negative association?  Since no statistics or direct comparisons to healthy dogs were performed in this study, you must state that this observation is a trend in your data and nothing more.

 

Finally, to address the authors fears of redundancy in their response to the original manuscript comments:  Scientific research articles are redundant.  I urge the authors to approach writing from the vantage point of their future readers.  Your readers should be able to read each section out of order and/or in isolation and still be able to understand what was done.  The difference among the various sections basically is in the level of detail presented.  Furthermore, your readers should be able to understand the work if they read through the Figures and Tables without the aid of the main text – and vice versa (i.e., if your reader is unable to see the Figures/Tables, the main text should be of sufficient detail that these visual aids are merely confirmatory).

To conclude, I would reiterate that the authors have important information to share and have made several positive strides toward their goal of publication.  But some parts of the experimentation require more transparency.  Until the level of rigor can be more accurately established by these results, the claims made in the discussion cannot be properly evaluated.

 

Comments on the Quality of English Language

Only minor edits are required to correct a handful of typos.

Author Response

Please see attachment 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Improvements were made to the manuscript.

Author Response

Thank you very much for taking the time to review our manuscript.