Antimicrobial Therapies for Early-Onset Group B Streptococcal Sepsis: Insights from an Italian Multicenter Study

Response to Reviewer 1 Comments

Comments 1: Line 77-79 please explain the fatality rate of GBS.

Response 1: Changed as suggested

Comments 2: Please need to explain the sources and subtype of GBS

Response 2: Our study investigates antibiotic treatments for early-onset GBS infections, which are invariably of maternal origin (as is well known by those working in the field of neonatal GBS infections). Information on the serotypes has already been published elsewhere (see DOI: 10.3390/microorganisms9122579).

Comments 3: Many information is missing in introduction. Please explain clearly.

Response 3: Please clarify more clearly what the reviewer is referring to.

Comments 4: Table 1 number of N should be increase. It is very less to say a novel findings. Thats why many data showed no statistical significant.

Response 4: We do not fully understand this comment. For authors familiar with this field, our population is unusually large; furthermore, we are unaware of previous studies that have examined in detail antibiotic therapies in early-onset GBS infection. If the reviewer is aware of any, please let us know.

Comments 5: Positive vaginal-rectal screening swab why too many number is missing ?

Response 5: Antenatal screening (whose results are available at the time of delivery) are performed at ≥ 35 weeks gestation; in contrast, screening is not performed under 35 weeks’ gestation, and information on GBS carriage may be unavailable at the time of delivery. In this case as well, for those familiar with neonatal GBS infections, this data is not surprising.

Comments 6: It would be more interesting if you add fiscal year.

Response 6: Please, explain what is “fiscal year” and what should we refer to?

Comments 7: Also you can add some seasonal birth for ex Summer or winter.

Response 7: Sorry, Group B Streptococcus is not a seasonal infection

Comments 8: To be honest, there is no interesting or novel findings in your research. 

Response 8: We have nothing further to add.

Comments 9: You should add maternal and infant characteristics.

Response 9: See table 1

Comments 10: Discussing need more modification. It looks like you explain again results section.

Response 10: The discussion has been revised, also in accordance with the suggestions of the other reviewers

Comments 11: Line 351-364 and 379-389 no need too much explanation your result. Actually Response 11: in the discussion part you should add your result compare with other findings. The discussion has been revised, also in accordance with the suggestions of the other reviewers.

Comments 12: Total 200 cases is very small amount please increase the cases number.

Response 12: This comment suggests a lack of familiarity with neonatal GBS infections

Response to Reviewer 2 Comments

Comments 1: The manuscript provides limited information on the statistical methods used. Include a more comprehensive description of the statistical analyses performed. Specify any statistical tests used, definitions of significance levels, and whether adjustments were made for confounding variables. While the use of non-parametric tests (Mann-Whitney) and Chi-square tests is appropriate, more details about how continuous variables. If any adjustments for multiple comparisons were performed, please state this explicitly. The manuscript mentions that data were missing for several cases. Please provide a more detailed description of the extent of missing data and any sensitivity analyses or imputation methods used.

Response 1: We thank the Reviewer for this insightful comment. In response, we have expanded the “Statistical Analysis” section to provide a more comprehensive description of the methods used. Specifically, we have now detailed the statistical tests applied, including the use of non-parametric tests (Mann–Whitney U test) for continuous variables and Chi-square or Fisher’s exact tests for categorical variables, as appropriate. We have also clarified how continuous and categorical variables are represented in the manuscript (i.e., medians and interquartile ranges for continuous variables; counts and percentages for categorical variables). Furthermore, we have explicitly stated that all comparisons were unadjusted. No adjustments for multiple comparisons were performed, nor for missing data. However, a detailed description of the burden of missing data for each variable is reported in the text

Comments 2: The criteria for classifying therapies as 'adequate' or 'inadequate' are briefly mentioned but lack detailed justification. Elaborate on the specific guidelines or consensus statements used to define adequacy of therapy. Including references to international standards will strengthen the rationale behind the categorizations.

Response 2: We added a new reference (Fuchs, WHO 2018), including sources on the adequacy of antibiotic therapies, also in the definitions section (see Methods).         

Comments 3: While the study identifies deviations from AMS guidelines, it does not thoroughly explore the underlying reasons.

Expand the discussion to consider possible factors contributing to inappropriate antibiotic use, such as variability in clinical practices, lack of awareness of guidelines, or resource limitations. The limitations of the study are not fully addressed.

Response 3: For both comments, we added these limitations, as suggested

Comments 4: The manuscript highlights problems but offers limited actionable solutions. Offer specific recommendations for improving adherence to AMS guidelines.

Response 4: We thank the reviewer for this comment. However, a practical aspect of our study is to inform all centers about the antibiotic therapies administered and the opportunity to follow international recommendations to limit the use of unnecessary therapies. This aim has been added in Introduction and Conclusions. In the future, an additional goal could be the creation of an antibiotic stewardship team that fosters shared decision-making regarding intrapartum antibiotics and the initiation or discontinuation of neonatal antibiotic therapies, as recommended in the literature.

Response to Reviewer 3 Comments

3. Point-by-point response to Comments and Suggestions for Authors

Comments 1:

·      Abstract:

Typos highlighted in red

•          (GBS) early-onset sepsis (EOS) provides insight into clinicians' adherence to antimicrobial

•          whereas 165 (82.5%) developed symptoms (56 of them - 0%- had severe disease) 62

•          were preterm newborns under 34 weeks’ gestation). Based on the available information, 64

The results section of the abstract is very dense. break it down for easier reading. You could separate the incidence, adequacy of therapy and mortality.

Response 1:

To improve reading, we summarized some results, as suggested. However we cannot add the overall incidence for the reasons reported in Methods

Comments 2:

Mention the implications of inappropriate antibiotic use in the conclusion.

Response 2:

Mentioned, as suggested.

Comments 3:

The study period is from 2003–2024, explain why this study period is chosen and how it reflects changing clinical practices on GBD EOS in the introduction” and “Discuss bias of selection criteria of Emilia-Romagna and the underrepresentation of centers outside Emilia-Romagna”

Response 3:

We clarified in Methods that the study's starting year coincides with the establishment of the GBS surveillance network in Emilia-Romagna. Since 2016, we have expanded the surveillance to include centers outside the Emilia-Romagna region. Given that 82% of the cases come from the Emilia-Romagna region, we do not believe that cases from outside the region will substantially distort the results.

Comments 4:

Clarify how missing data may bias the findings, especially regarding adequacy and duration of antibiotic treatment.

Response 4:

In response, we have expanded the “Statistical Analysis” section to provide a more comprehensive description of the methods used. Specifically, we have now detailed the statistical tests applied, including the use of non-parametric tests (Mann–Whitney U test) for continuous variables and Chi-square or Fisher’s exact tests for categorical variables, as appropriate. We have also clarified how continuous and categorical variables are represented in the manuscript (i.e., medians and interquartile ranges for continuous variables; counts and percentages for categorical variables). Furthermore, we have explicitly stated that all comparisons were unadjusted. No adjustments for multiple comparisons were performed, nor for missing data. However, a detailed description of the burden of missing data for each variable is reported in the text.

Comments 5:

Highlight statistically significant results using bold text or asterisks in Table 1 & Table 2

Response 5:

Thank you, but this suggestion does not match with journals’ guidelines

Comments 6:

Why some cases received extended antibiotic courses and what biomarkers considered?

Response 6:

This is a major limitation of our study We added in the Discussion: Our study has important limitations. The lack of detailed information on the clinical criteria or biomarkers used to prolong antimicrobial therapy in these cases limits our ability to assess adherence to guidelines and the appropriateness of therapeutic decisions. Possible factors contributing to inappropriate antibiotic use, such as variability in clinical practices, lack of awareness of guidelines, or resource limitations. We were unable to retrieve the burden of these contributing factors.

 Comments 7:

Why there were 14 deaths could you provide the clinical context for it?

 Response 7:

Available information regarding causes of death is insufficient, and we added this limitation in the discussion. Furthermore, we added in the footnote of table 2: “among 14 case fatalities, 5 died within 24 hours from the onset of EOS, 6 from 1 to 7 days and 3 over the first week”

Comments 8:

In the discussion expand your comparison with recent European and North American research on neonatal sepsis management. Also avoid long and complex sentences.

Response 8:

Updated both in the Introduction and in Methods the reference to guidelines

Comments 9: Limitations of the study “Biomarker data and its impact on assessing therapy” and “Observed inter-center variability in antibiotic protocols”

Response 9: Updated (see limitations)

Response to Reviewer 4 Comments

Point-by-point response to Comments and Suggestions for Authors

Comments 1: In the manuscript is everywhere EOS (sepsis), while in the title is infection. I suggest to write in the title as well sepsis instead of infection, since is not the same.

Response 1: Changed, as suggested

Comments 2:  "risk factors for EOS present" could you give examples here?

Response 2:  Added in Methods, as suggested.

Comments 3:  Line 229: Please give the explanation for LP abbreviation.

Response 3:  We replaced the abbreviation.

Comments 4: “While the majority of new-borns received appropriate therapy, targeted interventions in antibiotic duration and selection could further optimize neonatal sepsis management”

Response 4: We agree with referee comment, and we changed the discussion as follows: Although targeted interventions in antibiotic duration and selection could further optimize neonatal sepsis management, a significant number of empirical therapies deviated from recommended guidelines.

Comments 1: It has been improved a lot. But still need to modify the discussion part. 

Response 1: We have included a table in the Methods section to simplify its understanding, and we have also expanded the Discussion as requested. Additionally, the English translation has been reviewed by our trusted translator.

Response 1: Thank you. We have included a table in the Methods section to simplify its understanding, and we have also expanded the Discussion as requested by the other referees.