Review for 10.1186/s12876-018-0807-x (2018)

Reviewer’s report
Title: Fecal carriage of multidrug-resistant Escherichia coli by community children in Southern Taiwan
Version: 1 Date: 16 Sep 2017
Reviewer: Jan Egil Afset
Reviewer's report:
Manuscript  BMGE-D-18-00426R1  Fecal  carriage  of  multidrug-resistant  Escherichia  coli  by
community children in Southern Taiwan
Comments:
Abstract P3, L 57 and P5, L 110-112: "fecal sample collected within 3 days of hospitalization". The
differentiation between community acquired and hospital acquired infection is  whether symptoms
develop within 3 days after admission- this includes transmission and incubation period. It is possible
that transmission leading to asymptomatic carriage can occur within less than 3 days after admission to
hospital. This should be commented under discussion. 
P 3, L62-71: for small numbers it is better to use actual numbers rather than percentages.
P3, L 68: "80%"- it is not clear what is the denominator (80% of what?)
P4, L81 and throughout the manuscript: use of the term "strain". It is common practice to use the term
"isolate" for a pure culture from a certain site (eg patient sample), while "strain" is used when the
isolate is characterized to some degree. In this sentence it would be better to write eg. "the E. coli
species is heterogeneous, and includes both commensal and pathogenic bacteria".
P4, L 98: "was" rather than "is".
P5, L105: including children with gastroenteritis may cause bias, since this infection may lead to a
temporary change in the intestinal flora with dominance of pathogenic bacteria. Since such bacteria are
more often exposed to antibiotic treatment, it is possible that such bacteria may be non-susceptible to
antibiotics more often than commensals. This should be mentioned in the discussion. 
P5, L110: "All participants provided informed consent": how was consent given for children <12-16
years- did their parents give consent? This should be specified.
P5, L116-118: culture of fecal samples and identification of E. coli based on blue color of CHROMagar
ECC: in reference 14 95/114 blue colonies from water samples from river water were confirmed as E.
coli. Other species that were blue were Enterobacter, Klebisella and Citrobacter, species which are not
uncommon in intestinal flora of humans. Confirmation of the E.coli strains with an alternative method
would therefore be advisable- at least the possibility of misidentification should be mentioned.
 P5, L121: Most persons would have several genotypes of E. coli in their intestines. Selection of only
one isolate per sample for susceptibility testing would most likely underestimate the prevalence of
resistance among E. coli in each subject. This should be mentioned under discussion.
P6, L125-133: 1) how ESBL positivity was confirmed is not clear: from results table 1 13 isolates were
R to Cefpirome, 21 to cefotaxime and 31 to Cefotaxime. Using effect of clavulanic acid will  help
identify the most common ESBLs, but not those ESBL-types which are not inhibited by clavulanic
acid.  2) Was an alternative test used confirmation of ESBL?
P6, L127-129 and 134: regarding breakpoints used for SIR classification: it is referred to a document
which is not open source. They should therefore write out the specific breakpoints used either in the
text, in table or as supplementary materials. They should also state which 
P7, L160: E. coli was isolated from 169 (66%) of 255 children. Alhough it happens that E. coli is
present in a stool culture, it is not this common. It may therefore seem that the method utilized in this
study had low sensitivity for culture of E. coli. Did they check the detection limit of the culture
method?
P7, L170: Table 2: the presentation of results in this table is constructed like a flowchart rather than a
table, which makes it difficult to read, since there is no information give to the left of each column. I
believe it would be better to present the information in a regular table. Another aspect is that sequence
type is a better phylogenetic marker than O-serogroup- I therefore suggest that these two should switch
places, as suggested in the table below:
ST131 (n=17) Non ST 131 (n=140)
O25bNonO25b O25bNonO25b
ESBL + (n=13) 7 4 2 0
ESBL – (n=144) 3 3 14 124
Cipro R (n=29) 6 1 4 18
Cipro S (n=128) 4 2 12 110
P8, L185: 80% of what?
P8, L197: 20 references to this sentence. It is unnecessary to list so many references, choose few recent
ones from different geographic areas.
P9, L218: On the previous page they list 20 references. Here they mention only one reference from
Africa: I miss comparison of their results, in addition to other regions of the world, also with countries
in the same geographic region.
P10, L229-231: The description of the previous studies in this paragraph contains to much information
making it difficult to see how they support the statement in this sentence. I recommend that the authors
try to extract exactly what results  supports this statement.
P10, L234-35: "By contrast", better "In contrast"?
P10,  L238:  "69.23%":  1)  small  numbers  (9/13)  should  primarily be  written  in  numbers  because
percentages does not give much meaning, 2) the low numbers does at least not warrant use of decimals.
References: the list of references should be shortened.
Are the methods appropriate and well described?
If not, please specify what is required in your comments to the authors.
No
Does the work include the necessary controls?
If not, please specify which controls are required in your comments to the authors.
Unable to assess
Are the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
No
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.
I am able to assess the statistics
Quality of written English
Please indicate the quality of language in the manuscript:
Needs some language corrections before being published
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