Reviewer’s report
Title:  The analysis of virulence factors and antibiotic resistance between Helicobacter pylori strains  
isolated from gastric antrum and body
Version: 0 Date: 01 Apr 2019
Reviewer: Erik Oliver Glocker
Reviewer's report:
Seo et al. have analysed antibiotic resistance and virulence factors of H. pylori strains isolated from  
gastric antrum and corpus of H. pylori infected individuals. Virulence factors were identified by PCR  
and sequencing, comparison of paired H. pylori isolates (antrum vs corpus) was carried out by RAPD  
fingerprinting. 
They found that some patients carried H. pylori with different virulence factors and antimicrobial  
resistance patterns what then need to get considered in eradication therapies in order to avoid possible  
treatment failures.
The methods used are sound and the conclusions drawn are correct, but I am concerned about some  
shortcomings of the manuscript. 
Major concern:
1) Even though the manuscript is interesting and well-written, the findings are not novel. There are  
several reports that have demonstrated different H. pylori with different antimicrobial susceptibilities in  
the stomach. In case two samples from corpus and antrum are microbiologically examined and their  
antimicrobial  susceptibility tested,  routine  diagnostic  laboratories  usually  state  the  more  resistant  
isolates on clinical reports. 
2) The discussion is not acceptable as it reads like a mix of results and discussion. Please focus on the  
discussion and do not repeat results. 
Minor concerns:
3) The number of patients included is low (n=80)
4) Figure 2 is not needed and may be deleted
5) Discussion section, lines 201 through 203: "In our study, antibiotic resistance rates between 2006-
2008  were  15%  for  clarithromycin,  levofloxacin,  and  moxifloxacin,  0%  for  amoxicillin  and  
tetracycline, and 55% for metronidazole (Table 4)." Don't understand this; the samples tested were  
from 2006 through 2008? How were these percentages worked out? As the number of samples is low, I  
would not mention these percentages. 
6) Discussion section, lines 213 through 215: 
"Instead, profiles of virulence factors and antibiotic resistance patterns were thoroughly investigated,  
which allow us to predict the clinical course of the disease and the response to the eradication treatment  
to some degree." I recommend deleting this sentence. Even though you know a resistance pattern, one  
does not necessarily may predict treatment outcome. 
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
Yes
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
Yes
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Yes
Are you able to assess any statistics in the manuscript or would you recommend an additional  
statistical review?
If  an  additional  statistical  review  is  recommended,  please  specify  what  aspects  require  further  
assessment in your comments to the editors.
Not relevant to this manuscript
Quality of written English
Please indicate the quality of language in the manuscript:
Acceptable
Declaration of competing interests
Please complete a declaration of competing interests, considering the following questions:
1. Have you in the past five years received reimbursements, fees, funding, or salary from an
organisation that may in any way gain or lose financially from the publication of this
manuscript, either now or in the future?
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose
financially from the publication of this manuscript, either now or in the future?
3. Do you hold or are you currently applying for any patents relating to the content of the
manuscript?
4. Have you received reimbursements, fees, funding, or salary from an organization that holds
or has applied for patents relating to the content of the manuscript?
5. Do you have any other financial competing interests?
6. Do you have any non-financial competing interests in relation to this paper?
If you can answer no to all of the above, write 'I declare that I have no competing interests' below. If  
your reply is yes to any, please give details below.
I declare that I have no competing interests
I agree to the open peer review policy of the journal. I understand that my name will be included on my  
report to the authors and, if the manuscript is accepted for publication, my named report including any  
attachments I upload will be posted on the website along with the authors' responses. I agree for my  
report to be made available under an Open Access Creative Commons CC-BY license  
(http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments which I do not wish to  
be included in my named report can be included as confidential comments to the editors, which will not  
be published.
I agree to the open peer review policy of the journal
Reviewer’s report
Title:  The analysis of virulence factors and antibiotic resistance between Helicobacter pylori strains  
isolated from gastric antrum and body
Version: 0 Date: 01 Apr 2019
Reviewer: Erik Oliver Glocker
Reviewer's report:
Seo et al. have analysed antibiotic resistance and virulence factors of H. pylori strains isolated from  
gastric antrum and corpus of H. pylori infected individuals. Virulence factors were identified by PCR  
and sequencing, comparison of paired H. pylori isolates (antrum vs corpus) was carried out by RAPD  
fingerprinting. 
They found that some patients carried H. pylori with different virulence factors and antimicrobial  
resistance patterns what then need to get considered in eradication therapies in order to avoid possible  
treatment failures.
The methods used are sound and the conclusions drawn are correct, but I am concerned about some  
shortcomings of the manuscript. 
Major concern:
1) Even though the manuscript is interesting and well-written, the findings are not novel. There are  
several reports that have demonstrated different H. pylori with different antimicrobial susceptibilities in  
the stomach. In case two samples from corpus and antrum are microbiologically examined and their  
antimicrobial  susceptibility tested,  routine  diagnostic  laboratories  usually  state  the  more  resistant  
isolates on clinical reports. 
2) The discussion is not acceptable as it reads like a mix of results and discussion. Please focus on the  
discussion and do not repeat results. 
Minor concerns:
3) The number of patients included is low (n=80)
4) Figure 2 is not needed and may be deleted
5) Discussion section, lines 201 through 203: "In our study, antibiotic resistance rates between 2006-
2008  were  15%  for  clarithromycin,  levofloxacin,  and  moxifloxacin,  0%  for  amoxicillin  and  
tetracycline, and 55% for metronidazole (Table 4)." Don't understand this; the samples tested were  
from 2006 through 2008? How were these percentages worked out? As the number of samples is low, I  
would not mention these percentages. 
6) Discussion section, lines 213 through 215: 
"Instead, profiles of virulence factors and antibiotic resistance patterns were thoroughly investigated,  
which allow us to predict the clinical course of the disease and the response to the eradication treatment  
to some degree." I recommend deleting this sentence. Even though you know a resistance pattern, one  
does not necessarily may predict treatment outcome. 
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
Yes
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
Yes
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Yes
Are you able to assess any statistics in the manuscript or would you recommend an additional  
statistical review?
If  an  additional  statistical  review  is  recommended,  please  specify  what  aspects  require  further  
assessment in your comments to the editors.
Not relevant to this manuscript
Quality of written English
Please indicate the quality of language in the manuscript:
Acceptable
Declaration of competing interests
Please complete a declaration of competing interests, considering the following questions:
1. Have you in the past five years received reimbursements, fees, funding, or salary from an
organisation that may in any way gain or lose financially from the publication of this
manuscript, either now or in the future?
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose
financially from the publication of this manuscript, either now or in the future?
3. Do you hold or are you currently applying for any patents relating to the content of the
manuscript?
4. Have you received reimbursements, fees, funding, or salary from an organization that holds
or has applied for patents relating to the content of the manuscript?
5. Do you have any other financial competing interests?
6. Do you have any non-financial competing interests in relation to this paper?
If you can answer no to all of the above, write 'I declare that I have no competing interests' below. If  
your reply is yes to any, please give details below.
I declare that I have no competing interests
I agree to the open peer review policy of the journal. I understand that my name will be included on my  
report to the authors and, if the manuscript is accepted for publication, my named report including any  
attachments I upload will be posted on the website along with the authors' responses. I agree for my  
report to be made available under an Open Access Creative Commons CC-BY license  
(http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments which I do not wish to  
be included in my named report can be included as confidential comments to the editors, which will not  
be published.
I agree to the open peer review policy of the journal
Please review this paper.
user
Reviewer’s report
Title:  The analysis of virulence factors and antibiotic resistance between Helicobacter pylori strains  
isolated from gastric antrum and body
Version: 0 Date: 01 Apr 2019
Reviewer: Erik Oliver Glocker
Reviewer's report:
Seo et al. have analysed antibiotic resistance and virulence factors of H. pylori strains isolated from  
gastric antrum and corpus of H. pylori infected individuals. Virulence factors were identified by PCR  
and sequencing, comparison of paired H. pylori isolates (antrum vs corpus) was carried out by RAPD  
fingerprinting. 
They found that some patients carried H. pylori with different virulence factors and antimicrobial  
resistance patterns what then need to get considered in eradication therapies in order to avoid possible  
treatment failures.
The methods used are sound and the conclusions drawn are correct, but I am concerned about some  
shortcomings of the manuscript. 
Major concern:
1) Even though the manuscript is interesting and well-written, the findings are not novel. There are  
several reports that have demonstrated different H. pylori with different antimicrobial susceptibilities in  
the stomach. In case two samples from corpus and antrum are microbiologically examined and their  
antimicrobial  susceptibility tested,  routine  diagnostic  laboratories  usually  state  the  more  resistant  
isolates on clinical reports. 
2) The discussion is not acceptable as it reads like a mix of results and discussion. Please focus on the  
discussion and do not repeat results. 
Minor concerns:
3) The number of patients included is low (n=80)
4) Figure 2 is not needed and may be deleted
5) Discussion section, lines 201 through 203: "In our study, antibiotic resistance rates between 2006-
2008  were  15%  for  clarithromycin,  levofloxacin,  and  moxifloxacin,  0%  for  amoxicillin  and  
tetracycline, and 55% for metronidazole (Table 4)." Don't understand this; the samples tested were  
from 2006 through 2008? How were these percentages worked out? As the number of samples is low, I  
would not mention these percentages. 
6) Discussion section, lines 213 through 215: 
"Instead, profiles of virulence factors and antibiotic resistance patterns were thoroughly investigated,  
which allow us to predict the clinical course of the disease and the response to the eradication treatment  
to some degree." I recommend deleting this sentence. Even though you know a resistance pattern, one  
does not necessarily may predict treatment outcome. 
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
Yes
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
Yes
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
Yes
Are you able to assess any statistics in the manuscript or would you recommend an additional  
statistical review?
If  an  additional  statistical  review  is  recommended,  please  specify  what  aspects  require  further  
assessment in your comments to the editors.
Not relevant to this manuscript
Quality of written English
Please indicate the quality of language in the manuscript:
Acceptable
Declaration of competing interests
Please complete a declaration of competing interests, considering the following questions:
1. Have you in the past five years received reimbursements, fees, funding, or salary from an
organisation that may in any way gain or lose financially from the publication of this
manuscript, either now or in the future?
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose
financially from the publication of this manuscript, either now or in the future?
3. Do you hold or are you currently applying for any patents relating to the content of the
manuscript?
4. Have you received reimbursements, fees, funding, or salary from an organization that holds
or has applied for patents relating to the content of the manuscript?
5. Do you have any other financial competing interests?
6. Do you have any non-financial competing interests in relation to this paper?
If you can answer no to all of the above, write 'I declare that I have no competing interests' below. If  
your reply is yes to any, please give details below.
I declare that I have no competing interests
I agree to the open peer review policy of the journal. I understand that my name will be included on my  
report to the authors and, if the manuscript is accepted for publication, my named report including any  
attachments I upload will be posted on the website along with the authors' responses. I agree for my  
report to be made available under an Open Access Creative Commons CC-BY license  
(http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments which I do not wish to  
be included in my named report can be included as confidential comments to the editors, which will not  
be published.
I agree to the open peer review policy of the journal
assistant