Reviewer's report
Title:DPO multiplex PCR as an alternative to culture and susceptibility testing to
detect Helicobacter pylori and its resistance to clarithromycin.
Version: 1Date:19 September 2011
Reviewer: Manfred Kist
Reviewer's report:
The authors have evaluated the performance of a “ready-to-use” molecular
diagnostic kit for detection of H. pylori and its susceptibility to clarithromycin in
gastric specimens, in comparison with culture as the “gold standard”, and an “in
house” real-time PCR technique. For this purpose they applied a retrospective
study design, based on frozen gastric specimens held on a stock of diagnostic
specimens. They used a recently described modified PCR technology “dual
priming oligonucleotide-PCR(DPO-PCR)with the potential to markedly reduce
unspecificity. This technique has been evaluated before by a Korean group (cited
and discussed by the authors) using basically a comparable design but applying
“disk diffusion”, which is not a generally accepted technique for testing
antimicrobial susceptibility.
The authors found the method nearly adequate to the in-house real-time PCR,
nearly as accurate as culture and phenotypical susceptibility testing, but of better
sensitivity. A problem of the new methodology, discussed by the authors, is the
possibility of false negative results as a consequence of the particular structure of
the primers used.
- Major Compulsory Revisions
No major compulsory revisions demanded
- Minor Essential Revisions
No minor essential revisions demanded
- Discretionary Revisions
Results,
p. 7, 2nd paragraph, lines 3 – 4: are their possible reasons for missing 16
biopsies by culture? What about histology in these cases? This result might be
discussed.
Discussion,
p. 11, 1st paragraph:
1. The authors conclude the Seeplex ClaR-H.pylori an “excellent alternative to
culture”. I would like to suggest that the authors should have in mind that
whenever possible culture should be done, and only in cases when classical
microbiology fails, the use of molecular methods are really indicated. The
rationale behind is that not only clarithromycin resistance is of interest but also
other antimicrobials are, like tetracyclin, quinolones, rifamicins, and
metronidazole. The authors might include these aspects in the discussion.
2. The discussion as a total appears a bit long and might be shortened
appropriately.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests
Reviewer's report
Title:DPO multiplex PCR as an alternative to culture and susceptibility testing to
detect Helicobacter pylori and its resistance to clarithromycin.
Version: 1Date:19 September 2011
Reviewer: Manfred Kist
Reviewer's report:
The authors have evaluated the performance of a “ready-to-use” molecular
diagnostic kit for detection of H. pylori and its susceptibility to clarithromycin in
gastric specimens, in comparison with culture as the “gold standard”, and an “in
house” real-time PCR technique. For this purpose they applied a retrospective
study design, based on frozen gastric specimens held on a stock of diagnostic
specimens. They used a recently described modified PCR technology “dual
priming oligonucleotide-PCR(DPO-PCR)with the potential to markedly reduce
unspecificity. This technique has been evaluated before by a Korean group (cited
and discussed by the authors) using basically a comparable design but applying
“disk diffusion”, which is not a generally accepted technique for testing
antimicrobial susceptibility.
The authors found the method nearly adequate to the in-house real-time PCR,
nearly as accurate as culture and phenotypical susceptibility testing, but of better
sensitivity. A problem of the new methodology, discussed by the authors, is the
possibility of false negative results as a consequence of the particular structure of
the primers used.
- Major Compulsory Revisions
No major compulsory revisions demanded
- Minor Essential Revisions
No minor essential revisions demanded
- Discretionary Revisions
Results,
p. 7, 2nd paragraph, lines 3 – 4: are their possible reasons for missing 16
biopsies by culture? What about histology in these cases? This result might be
discussed.
Discussion,
p. 11, 1st paragraph:
1. The authors conclude the Seeplex ClaR-H.pylori an “excellent alternative to
culture”. I would like to suggest that the authors should have in mind that
whenever possible culture should be done, and only in cases when classical
microbiology fails, the use of molecular methods are really indicated. The
rationale behind is that not only clarithromycin resistance is of interest but also
other antimicrobials are, like tetracyclin, quinolones, rifamicins, and
metronidazole. The authors might include these aspects in the discussion.
2. The discussion as a total appears a bit long and might be shortened
appropriately.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests
Please review this paper.
user
Reviewer's report
Title:DPO multiplex PCR as an alternative to culture and susceptibility testing to
detect Helicobacter pylori and its resistance to clarithromycin.
Version: 1Date:19 September 2011
Reviewer: Manfred Kist
Reviewer's report:
The authors have evaluated the performance of a “ready-to-use” molecular
diagnostic kit for detection of H. pylori and its susceptibility to clarithromycin in
gastric specimens, in comparison with culture as the “gold standard”, and an “in
house” real-time PCR technique. For this purpose they applied a retrospective
study design, based on frozen gastric specimens held on a stock of diagnostic
specimens. They used a recently described modified PCR technology “dual
priming oligonucleotide-PCR(DPO-PCR)with the potential to markedly reduce
unspecificity. This technique has been evaluated before by a Korean group (cited
and discussed by the authors) using basically a comparable design but applying
“disk diffusion”, which is not a generally accepted technique for testing
antimicrobial susceptibility.
The authors found the method nearly adequate to the in-house real-time PCR,
nearly as accurate as culture and phenotypical susceptibility testing, but of better
sensitivity. A problem of the new methodology, discussed by the authors, is the
possibility of false negative results as a consequence of the particular structure of
the primers used.
- Major Compulsory Revisions
No major compulsory revisions demanded
- Minor Essential Revisions
No minor essential revisions demanded
- Discretionary Revisions
Results,
p. 7, 2nd paragraph, lines 3 – 4: are their possible reasons for missing 16
biopsies by culture? What about histology in these cases? This result might be
discussed.
Discussion,
p. 11, 1st paragraph:
1. The authors conclude the Seeplex ClaR-H.pylori an “excellent alternative to
culture”. I would like to suggest that the authors should have in mind that
whenever possible culture should be done, and only in cases when classical
microbiology fails, the use of molecular methods are really indicated. The
rationale behind is that not only clarithromycin resistance is of interest but also
other antimicrobials are, like tetracyclin, quinolones, rifamicins, and
metronidazole. The authors might include these aspects in the discussion.
2. The discussion as a total appears a bit long and might be shortened
appropriately.
Level of interest: An article of importance in its field
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests
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