Antibiotic Susceptibility and Clarithromycin Resistance Determinants in Helicobacter pylori in the Northeast of Spain: A One-Year Prospective Study

Round 1

Reviewer 1 Report

·   This manuscript describes the antibiotic susceptibility and clarithromycin resistance determinants in Helicobacter pylori from patient in Northeast of Spain. Overall, the manuscript is well designed and written but materials and methods need to be described in more details, correction of data needs to be rechecked, wrong calculation on the percentages is presented. The results are very useful for public health. I have comments/questions for the authors as follows.

·       Authors report the general characteristics of patients in the results section. Collection of patient information should be mentioned in the materials and methods section.

·       Authors should describe the decision criteria used for evaluation of pathological anatomy of H. pylori.

·       Real time PCR has been used in this study. Authors should describe the details of real time PCR such as primers, condition, probe etc. or give the reference of the method used.

·       Since, 641 culture biopsies were subjected to microbiological test and H. pylori was isolated in 148 of these specimens. The positivity rate should be 23.1% instead of 22.2%.  

·       Clarithromycin resistance should be 12.1% (17/141) instead of 12%.

·       Author reports the Correlation between Pathological Anatomy and culture in 2.4. Statistical test should be used in order to conclude that there was a good correlation between the two methods.

·       Since MIC level were mentioned the results section, EUCAST breakpoint of different antimicrobial used in this study should be mentioned in materials and methods to give a clearer picture to the readers.

·       There were 10 samples that gives negative results by culture method but positive by PCR. These results should be included under 2.1 clinical and epidemiological data.

·       In the 2.5 Empirical antibiotic treatment, there is wrong calculation of 40.5%, it should be 41.0%.

·       More than half of Clarithromycin resistance isolates show very high MIC values especially when comparing with very low MIC breakpoint. It would give more value to this paper if authors emphasis more on this results in the discussion and the abstract.

·       As the title contains “antibiotic susceptibility patterns” but it was not mentioned both in the abstract and the discussion section. I would suggest authors to change from “antibiotic susceptibility patterns” to “antibiotic susceptibility” in the title.

Author Response

Reviewer 1

• Authors report the general characteristics of patients in the results section. Collection of patient information should be mentioned in the materials and methods section.

      Answer: We have included this point in the method section as suggested.

• Authors should describe the decision criteria used for evaluation of pathological anatomy of H. pylori.

Answer: We have checked all pathological anatomy results of all patients with culture request. We have included the following sentence in the method section to make it clearer:

“All available results from Pathological Anatomy (PA) were analysed”.

• Real time PCR has been used in this study. Authors should describe the details of real time PCR such as primers, condition, probe etc. or give the reference of the method used.

We have added the name of the viewer software and the reference of the evaluation of this commercial kit.

• Since, 641 culture biopsies were subjected to microbiological test and H. pyloriwas isolated in 148 of these specimens. The positivity rate should be 23.1% instead of 22.2%.  

Answer: We have modified these data as suggested

• Clarithromycin resistance should be 12.1% (17/141) instead of 12%.

Answer: We have modified these data as suggested.

• Author reports the Correlation between Pathological Anatomy and culture in 2.4. Statistical test should be used in order to conclude that there was a good correlation between the two methods.

We have included the following sentence in the methods section

“The overall agreement between Microbiology and PA results was evaluated and measured using Cohens' kappa coefficient (κ).”

• Since MIC level were mentioned the results section, EUCAST breakpoint of different antimicrobial used in this study should be mentioned in materials and methods to give a clearer picture to the readers.

Answer: We have included the requested information in the method section.

• There were 10 samples that gives negative results by culture method but positive by PCR. These results should be included under 2.1 clinical and epidemiological data.

      Answer: We have included this information under 2.1

• In the 2.5 Empirical antibiotic treatment, there is wrong calculation of 40.5%, it should be 41.0%.

Answer: We have changed this percentage.

• More than half of Clarithromycin resistance isolates show very high MIC values especially when comparing with very low MIC breakpoint. It would give more value to this paper if authors emphasis more on this results in the discussion and the abstract.

Answer: We have included these points in the abstract, results and discussion

• As the title contains “antibiotic susceptibility patterns” but it was not mentioned both in the abstract and the discussion section. I would suggest authors to change from “antibiotic susceptibility patterns” to “antibiotic susceptibility” in the title.

Answer: We have changed the title as required.

 

Reviewer 2 Report

  In the article "Antibiotic susceptibility patterns and clarithromycin resistance determinants in Helicobacter pylori in Northeast of Spain. A one-year prospective study ", the authors  presented the antibiotic resistance profile of H. pylori  and the main mechanisms involved in clarithromycin resistance.  If clarithromycin triple therapy with amoxicillin, clarithromycin and PPI have been the most frequently used first-line treatments the non-bismuth quadruple therapy with PPI, amoxicillin, clarithromycin and metronidazole could  be implemented. The detection of the resistance to  clarithromycin and metronidazole is mandatory to decide the therapy schema.  

 

Author Response

There were not points to review from Reviewer 2

Reviewer 3 Report

1- key words . what difference between  clarithromycin resistance and  antibiotic resistance.

2. Discuss: One clarithromycin resistant isolate with a 136 MIC value of 16 mg/L did not present any of the tested mutations.

3- Antimicrobial resistance patterns of H. pylori were previously unknown in our area. what area

 

Author Response

Reviewer 3

• 1.Key words . what difference between  clarithromycin resistance and  antibiotic resistance.

Answer: Thank you for your comments. We have changed “antibiotic resistance” and added “triple therapy”

2. Discuss: One clarithromycin resistant isolate with a 136 MIC value of 16 mg/L did not present any of the tested mutations.

Answer: We have included this point in discussion.

3- Antimicrobial resistance patterns of H. pylori were previously unknown in our area. what area

Answer: We have added, “covering an area of the Northeast of Spain with approximately 340,000 inhabitants” in Methods