Isolation of Pathogenic Bacteria from Dairy Cow Mastitis and Correlation of Biofilm Formation and Drug Resistance of Klebsiella pneumoniae in Jiangsu, China

Round 1

Reviewer 1 Report

A good attempt has been made to demonstrate the pathogens and their resistnace pattern in mastitis cases in specifc area. However, the proportion of large number of mixed infections and that too with 3-4 pathogens  is a very  unusal pattern and needs to justify. Also, please rule out that it is a not a contamination during sampling.  

The mansuscript needs editing for english language improvement. 

Author Response

Dear reviewer

Thanks for the suggestions for our manuscript. As an increasing amount of mixed infection has been found in the area, we believe that it is still a tricky disease that brings difficulties in the selection of antimicrobial agents for treatment. Also, the contamination has been avoided during the sampling and all of the statement has been added in the revised manuscript with yellow highlight. 

Reviewer 2 Report  

Dear Editor,

Title Isolation of pathogenic bacteria from dairy cow mastitis and correlation of biofilm formation and drug resistance of Klebsiella pneumoniae in Jiangsu, China

1.      Summary

The prevalence of pathogenic bacteria in the mammary glands of dairy cows was notably high, with frequent instances of mixed bacterial infections. Various environmental pathogenic bacteria were identified, with Klebsiella pneumoniae being the most frequently detected. Among the 68 strains of K. pneumoniae studied, they exhibited varying degrees of susceptibility to different antimicrobial drugs, but displayed robust resistance to β-lactam drugs. Furthermore, a high incidence of β-lactamase genes was observed, and there was a strong correlation between the formation of K. pneumoniae biofilm and the phenotype of tetracycline resistance. This research offers valuable insights into understanding the prevalence of mastitis-causing pathogens in lactating cows and provides a foundation for the judicious use of antimicrobial agents in the treatment of K. pneumoniae-induced mastitis.

2.  General comments

The work is interset, but it needs minor revision

please substitute ethical certificate with number from your local institute

Reference should follow the journal construction 

3.   Constructive criticism

You should be inserting Figure for electrophoresis resistant or biofilm  

need minor revision 

Author Response

Dear reviewer

Thanks for your suggestions for our manuscript. We have modified the suggested information in the revised manuscript. Please kindly find them in the revised one with blue highlights.

Reviewer 3 Report

1.    Formatting error (e.g., space between words).

2.    Why have the authors compared four farms? Are there any differences between these farms? For example, the Type of farm and the difference between each farm, cattle density, farm management, and especially the environment. These may affect the in- and reinfection of these pathogenic bacteria. Please describe these in the material and methods in the discussion (line no. 213-230).

3.    Line 100, ….. 0.5 McBurney? Do the authors mean 0.5 MacFarland?

4.    Line 157-158, please provide the number of bacterial species detected from clinical and subclinical mastitis. These numbers could support the finding of pathogenic strains related to presenting clinical signs.

5.    In Table 1, the numbers of isolated bacteria in each farm should be present in this table.

6.    In Table 3, the number of positive gene in each gene should be present in this table.

7.    What does it mean for numbers in line 204 to 209? ……azithromycin resistance (0.296)……….tetracycline (0.287)…….

Author Response

1. Formatting error (e.g., space between words).

RE: Thanks for the comments. We have revised in the latest version of manuscript.

2. Why have the authors compared four farms? Are there any differences between these farms? For example, the Type of farm and the difference between each farm, cattle density, farm management, and especially the environment. These may affect the in- and reinfection of these pathogenic bacteria. Please describe these in the material and methods in the discussion (line no. 213-230).

RE: Thanks for the comment. We have added the information in the Discussion section.

3. Line 100, ….. 0.5 McBurney? Do the authors mean 0.5 MacFarland?

RE: Thanks for the comment. We have corrected the word in this section.

4. Line 157-158, please provide the number of bacterial species detected from clinical and subclinical mastitis. These numbers could support the finding of pathogenic strains related to presenting clinical signs.

RE: Thanks for your suggestions. The samples from this study were collected from the mastitis with clinical signs. There was a mistake we made in the context. We have modified it in the revised version. However, it is a valuable suggestion which helps us to identify the number of those cases in future sampling.

5. In Table 1, the numbers of isolated bacteria in each farm should be present in this table.

RE: We have added the information in the revised manuscript.

6. In Table 3, the number of positive gene in each gene should be present in this table.

 RE: We have added the information in the revised manuscript.

7. What does it mean for numbers in line 204 to 209? ……azithromycin resistance (0.296)……….tetracycline (0.287)…….

RE: The numbers mean the correlation for the genotype and phenotype of drug resistance.