Reviewer's report
Title:The protective effect of recombinant Lactococcus lactis oral vaccine on a
Clostridium difficile-infected animal model
Version: 5Date:6 March 2013
Reviewer: Martijn P Bauer
Reviewer's report:
The manuscript has become much more readable after the modifications.
However, I have some more comments.
Minor revisions
In general
The terms ‘secreted plasmid’ and ‘membrane-anchored plasmid’ suggest that the
plasmid is secreted and membrane-anchored, whereas this happens to the
protein for which the plasmid codes. It would be clearer if the name were
changed to ‘secreted protein plasmid’ or the groups were numbered or
something like that.
Why was cwaM6 chosen as one of the genes in the vaccine with cell
wall-anchored proteins?
What could be the advantage of membrane-anchored proteins as vaccine over
secreted proteins? Have the authors tried to demonstrate secreted proteins in
stool?
In the Discussion, the authors only refer to one article on humoral immunity in
CDI in animals, whereas there is a lot of literature on the role of the antibody
response in humans. The manuscript would improve if this literature would also
be taken into account.
Abstract
‘Is an important pathway’ or, rather, ‘may be an effective strategy’.
Introduction
Can a reference be given for the statement that CDI incidence is increasing in
China?
Please spell out CLDM the first time it is used.
2.2
‘Modification’ instead of ‘medication’.
2.4
‘Manufacturer’ instead of ‘manufacture’.
How was cytopathic effect scored in the neutralisation assay?
3.1; last line
One ‘no’ should be removed.
3.2
I do not understand the scores for the membrane-anchored group. Neither do I
understand why only the scores for this group are given. The figures are clear
enough by themselves. Were any of these differences statistically significant?
4.2 & 4.3
The authors state in paragraph 4.2 that because their animal model had been
treated with clindamycin after vaccination, recombinant L. lactis could not have
acted as a probiotic. My interpretation is that they assume all L. lactis are killed
by the clindamycin treatment. Is the MIC for clindamycin of this strain of L. lactis
known? Furthermore, this assumption could be stated more explicitly. On the
other hand, in the next paragraph, the authors explain the milder clinical course
of the animals that were given L. lactis with an empty plasmid by its acting as a
probiotic. They seem to assume that some L. lactis survive clindamycin
treatment.
The figures still have the names of the hamster groups used in the previous
version. Please change.
Could statistically significant differences be indicated in all figures?
It is difficult to read fig. 9.
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:The protective effect of recombinant Lactococcus lactis oral vaccine on a
Clostridium difficile-infected animal model
Version: 5Date:6 March 2013
Reviewer: Martijn P Bauer
Reviewer's report:
The manuscript has become much more readable after the modifications.
However, I have some more comments.
Minor revisions
In general
The terms ‘secreted plasmid’ and ‘membrane-anchored plasmid’ suggest that the
plasmid is secreted and membrane-anchored, whereas this happens to the
protein for which the plasmid codes. It would be clearer if the name were
changed to ‘secreted protein plasmid’ or the groups were numbered or
something like that.
Why was cwaM6 chosen as one of the genes in the vaccine with cell
wall-anchored proteins?
What could be the advantage of membrane-anchored proteins as vaccine over
secreted proteins? Have the authors tried to demonstrate secreted proteins in
stool?
In the Discussion, the authors only refer to one article on humoral immunity in
CDI in animals, whereas there is a lot of literature on the role of the antibody
response in humans. The manuscript would improve if this literature would also
be taken into account.
Abstract
‘Is an important pathway’ or, rather, ‘may be an effective strategy’.
Introduction
Can a reference be given for the statement that CDI incidence is increasing in
China?
Please spell out CLDM the first time it is used.
2.2
‘Modification’ instead of ‘medication’.
2.4
‘Manufacturer’ instead of ‘manufacture’.
How was cytopathic effect scored in the neutralisation assay?
3.1; last line
One ‘no’ should be removed.
3.2
I do not understand the scores for the membrane-anchored group. Neither do I
understand why only the scores for this group are given. The figures are clear
enough by themselves. Were any of these differences statistically significant?
4.2 & 4.3
The authors state in paragraph 4.2 that because their animal model had been
treated with clindamycin after vaccination, recombinant L. lactis could not have
acted as a probiotic. My interpretation is that they assume all L. lactis are killed
by the clindamycin treatment. Is the MIC for clindamycin of this strain of L. lactis
known? Furthermore, this assumption could be stated more explicitly. On the
other hand, in the next paragraph, the authors explain the milder clinical course
of the animals that were given L. lactis with an empty plasmid by its acting as a
probiotic. They seem to assume that some L. lactis survive clindamycin
treatment.
The figures still have the names of the hamster groups used in the previous
version. Please change.
Could statistically significant differences be indicated in all figures?
It is difficult to read fig. 9.
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:The protective effect of recombinant Lactococcus lactis oral vaccine on a
Clostridium difficile-infected animal model
Version: 5Date:6 March 2013
Reviewer: Martijn P Bauer
Reviewer's report:
The manuscript has become much more readable after the modifications.
However, I have some more comments.
Minor revisions
In general
The terms ‘secreted plasmid’ and ‘membrane-anchored plasmid’ suggest that the
plasmid is secreted and membrane-anchored, whereas this happens to the
protein for which the plasmid codes. It would be clearer if the name were
changed to ‘secreted protein plasmid’ or the groups were numbered or
something like that.
Why was cwaM6 chosen as one of the genes in the vaccine with cell
wall-anchored proteins?
What could be the advantage of membrane-anchored proteins as vaccine over
secreted proteins? Have the authors tried to demonstrate secreted proteins in
stool?
In the Discussion, the authors only refer to one article on humoral immunity in
CDI in animals, whereas there is a lot of literature on the role of the antibody
response in humans. The manuscript would improve if this literature would also
be taken into account.
Abstract
‘Is an important pathway’ or, rather, ‘may be an effective strategy’.
Introduction
Can a reference be given for the statement that CDI incidence is increasing in
China?
Please spell out CLDM the first time it is used.
2.2
‘Modification’ instead of ‘medication’.
2.4
‘Manufacturer’ instead of ‘manufacture’.
How was cytopathic effect scored in the neutralisation assay?
3.1; last line
One ‘no’ should be removed.
3.2
I do not understand the scores for the membrane-anchored group. Neither do I
understand why only the scores for this group are given. The figures are clear
enough by themselves. Were any of these differences statistically significant?
4.2 & 4.3
The authors state in paragraph 4.2 that because their animal model had been
treated with clindamycin after vaccination, recombinant L. lactis could not have
acted as a probiotic. My interpretation is that they assume all L. lactis are killed
by the clindamycin treatment. Is the MIC for clindamycin of this strain of L. lactis
known? Furthermore, this assumption could be stated more explicitly. On the
other hand, in the next paragraph, the authors explain the milder clinical course
of the animals that were given L. lactis with an empty plasmid by its acting as a
probiotic. They seem to assume that some L. lactis survive clindamycin
treatment.
The figures still have the names of the hamster groups used in the previous
version. Please change.
Could statistically significant differences be indicated in all figures?
It is difficult to read fig. 9.
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.
assistant