PONE-D-21-01468

Prevalence, serotype and antibiotic susceptibility of Group B Streptococcus isolated from pregnant women in Jakarta, Indonesia

PLOS ONE

Dear Dr. Putri,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Methodology used needs more clarifications and discussions needs improvements. 

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Iddya Karunasagar

Academic Editor

PLOS ONE

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Additional Editor Comments:

The reviewers have raised a number of questions on methodology used and made suggestions for improvements in interpretation and discussion. Please address all reviewer comments point by point.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Partly

Reviewer #3: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

Reviewer #2: No

Reviewer #3: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This limited study is one of many studies describing GBS prevalence in pregnant population but one of the few from Indonesia. It is original in so far that describe the prevalence, serotypes and antimicrobial susceptibility in this population. The study is a part of a wider study 'Effect of Air Pollution in Early Life on Infant and Maternal Health Project'. It appears to be a single centre study. Statistics: No sample size calculation for estimating GBS prevalence undertaken. Thus it is not clear how the sample size was chosen. Only univariate statistics are presented when assessing association of GBS with maternal demographics, conditions and outcomes. No confidence intervals provided for rates. Microbiology: No rectal swabs taken. So likely to underestimate rates. Swabs taken and stored at -80C. However no assessment of viability of GBS. Authors have not stated how long swabs were stored before culture. It is not clear how resistance to clindamycin was determined. It is unusual for clindamycin resistance rates to be higher than erythromycin resistance rates. Was inducible resistance tested? The discussion is satisfactory but suggest rephrase the sentence in lines 152/3 to state the rate reported in this study may be an underestimation as only vaginal swabs were collected.

There is no section describing the limitations of the study. Finally the findings of this limited study may not be generalizable.

Reviewer #2: Overall – a straightforward study, with findings similar to previous data from Indonesia in 2010. While serotypes are interesting as potential vaccine targets, MLST or WGS would give more discriminating data, allowing more discriminating molecular epidemiology. The data need a statistical analysis.

Title – ok

Abstract – ok

Main text

1. Line 43 – I don’t consider GBS a ‘diplococcus’; surely just a coccus, or cocci in chains.

2. Line 49/50. I don’t understand this sentence. Perhaps you mean ‘... especially in Africa, where 54% of estimated cases and 65% of all 50 fetal/infant deaths occur.’

3. Line 56; this is a very long sentence, and therefore hard to read. I suggest you break it up into 2 sentences. ‘In general, the prevalence of maternal GBS colonization is 18% worldwide, with considerable regional variation (11-35%). Almost all (98%) colonizing GBS are serotype I-IV, whereas serotype III is associated with invasive disease [5].

4. Line 57; do you mean serotypes I and IV? .. or serotypes Ia, Ib, II, III and IV?

5. Line 60 -61. This sentence is not clear. Does this data on Ia refer to GBS pairs, isolated from both mother and child pairs? Does it refer to invasive or just colonising GBS? You must be very specific, otherwise the reader won’t understand your message. Are you telling us that Ia accounts for 40% of invasive neonatal disease? Simply pasting data from a reference without telling us why you are doing so, or interpreting the data for readers, is unhelpful.

6. Line 75 – change to ... ‘... findings may contribute to new preventive strategies targeting ...’

7. Line 90 – you could delete ‘The content and objectives of the study were explained to the participants and their consent obtained by signature on the appropriate consent forms.’.

8. Line 92; change ‘eligible’ to ‘consented’

9. Table 1 is confusing, as you have calculated % data in columns. Most readers are interested in the % of positive or negative colonisation in each group, meaning the % data should be across rows, not columns. I don’t think the ‘Frequency’ column needs % data at all.

10. Line 126; the text says that there were no differences in rates but I don’t see any statistical analysis (comparing carriage v non-carriage in each category).

11. Fig 1 does not show any statistical analysis.

12. Delete Table 2, as all the data is in the text – lines 138 – 146.

13. Line 149 - 152; a long sentence. It would be easier to read if you cut it up.

14. Line 152 - 153; I think you mean ‘The true colonisation rate ...’

15. Line 163 – The sentence includes serotype V, but doesn’t include IV, but earlier you said (Line 57), that I-IV accounted for 98% of GBS. Please harmonise.

16. Line 189; I think this is a little unfair, as a summary of the reference you cite; they actually say ‘While overall resistance is still relatively rare, a recent study highlighted the increased incidence of PR-GBS in Japan, increasing from 2.3% in 2005–2006 to 14.7% in 2012/13.’ A balanced view is along the lines of 'While there are occasional reports of penicillin resistance, resistance is so rare that penicillin can be safely used empirically'.

Reviewer #3: Manuscript #: PONE-D-21-01468

Title: Prevalence, serotype and antibiotic susceptibility of Group B Streptococcus isolated from pregnant women in Jakarta, Indonesia

Authors: Dodi Safari; Septiani Madonna Gultom; Wisnu Tafroji; Athiya Azzahidah; Frida Soesanti; Miftahuddin Majid Khoeri; Ari Prayitno; Fabiana C. Pimenta; Maria da Gloria Carvalho; Cuno S. P. M. Uiterwaal; Nina Dwi Putri

Drs. D Safari et al collected clinical isolates of GBS from 177 pregnant women in Jakarta, Indonesia and performed serotying and drug susceptibility tests. This is a valuable manuscript because information from Southeast Asia is rare and well-written. There is no ethical and methodological problem and the information in this manuscript is very valuable.

I suggest one point. This manuscript lack description concerning the situation of prevention method in Indonesia. In Indonesia, is the intrapartum prophylaxis performed? Please mention the situation of GBS infection prevention method in Indonesia in the revised manuscript.

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Reviewer #1: Yes: Dr Guduru Gopal Rao

Reviewer #2: Yes: Timothy Barkham

Reviewer #3: No

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Prevalence, serotype and antibiotic susceptibility of Group B Streptococcus isolated from pregnant women in Jakarta, Indonesia

PONE-D-21-01468R1

Dear Dr. Putri,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Iddya Karunasagar

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

All reviewer comments have been addressed satisfactorily. One typographical error has been pointed out by one of the reviewers.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

Reviewer #3: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: I Don't Know

Reviewer #2: Yes

Reviewer #3: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The authors have attempted to address the comments of the reviewers. Future studies are necessary to confirm these observations

Reviewer #2: I saw one typo - on line 55/56 - ... 'where 54% of estimated cases and 65% of all 50 fetal/infant deaths occur.

Please remove the '50'.

Reviewer #3: Authors responded to my all comments and the revised manuscript became better. Therefore, I recommend the acceptance for the publication of this journal.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: G Gopal Rao

Reviewer #2: Yes: Timothy Barkham

Reviewer #3: No