Uses of Antibiotics in Ornamental Fish in Hong Kong and the Antibiotic Resistance in the Associated Zoonotic Pathogens
Round 1
Reviewer 1 Report
This research addresses concerning aquaculture industry practices of unregulated antibiotic usage in the ornamental fish, which may promote the emergence, introduction and transmission of treatment-resistant bacterial pathogens in domestic settings. The genera of bacteria assayed herein impose a severe public health burden, anticipated to continue into the forseeable future. Pseudomonas spp. account for a large fraction of nosocomial infections, P. aeruginosa being the most common cause of hospital-acquired pneumonia. Aromonas spp. cause gastroenteritis, and in some cases life-threatening necrotizing fasciculitis. Primary treatment for Aeromonas infection is with ciprofloxacin, though treatment-resistant strains exist, with high prevalence especially in Asia.
Detection of antibiotic-resistant bacterial strains by sequencing methods is complicated by the ubiquity of horizontal gene transfer. Here the authors circumvent that obstacle, testing antibiotic resistance directly and further exploring the potential relationship to residual antibiotics detected in fish-carrying water samples from a local Hong Kong fish market.
The data analysis methods used in Figure 1 should be clarified. The trend lines do not appear to have been generated by a simple linear regression. What the authors describe as the correlation coefficient is not Pearson’s r, but rather the coefficient of determination, R2. R2 reflects the portion of variance in the dependent variable explained by the independent variable, and is commonly considered as a measure of goodness-of-fit to the particular regression model chosen. The analyses may be appropriate, but require better description.
It is reasonable, as the authors suggest, that most correlations being weak and not statistically significant could be due development of antibiotic resistance prior to market distribution.
Author Response
Please see the attachment
Author Response File: 
Author Response.docx
Reviewer 2 Report
Positive comments:
1. The topic of the manuscript is relevant as it is related to uses of Antibiotics in Ornamental Fish in Hong Kong and the antibiotic Resistance in the Associated Zoonotic Pathogens;
2. The article is structured relatively well, having the necessary sections;
3. The literature review is detailed and cuts the current state of the problem;
4. The methods are described in detail and correctly;
5. The data are presented relatively adequately;
6. A reasonably good scholarly discussion has been made.
Negative comments and recommendations:
1. At the end of the literature review, the purpose of the research is not clearly stated;
2. Sulfonamides are not antibiotics but chemotherapeutics. Please correct the text where necessary!
3. You have two points with the same text - 2.3.1. Antibiotic Analysis /line 139/ and 2.4. Antibiotic Analysis /line 157/. Please refine the text!
4. Please zoom in figure 1 by about 15% for better visibility!
5. Please formulate specific conclusions after the discussion as required by the journal!
6. It would be good to make recommendations to the fish farming industry, which would be useful for the cultivation of ornamental fish.
Author Response
Please see the attachment
Author Response File: Author Response.docx
Reviewer 3 Report
Attached
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment
Author Response File: Author Response.docx
