The LiaSR Two-Component System Regulates Resistance to Chlorhexidine in Streptococcus mutans

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study investigates Chlorhexidine (CHX) resistance mechanisms in Streptococcus mutans, a major dental caries pathogen. Deletion of liaS and liaR genes increased sensitivity to CHX, while reducing efflux rates. qRT-PCR revealed LiaSR system-mediated upregulation of lmrB, aiding efflux. Mutants exhibited higher hydrophobicity, membrane depolarization, and unclear cell membrane borders, suggesting membrane disruption. However, surface charge remained unchanged. These findings shed light on LiaSR's role in CHX resistance, implicating membrane disturbance and potential inhibition of cell envelope stress response. The study offers novel insights into S. mutans' CHX resistance mechanisms.

Introduction:Background and context: The introduction provides a comprehensive background on the significance of the LiaSR system in bacterial physiology and its potential role in antibiotic resistance beyond CHX. This overview of LiaSR’s known functions helps contextualize its role in CHX resistance.

Citations and references: The introduction effectively incorporates relevant references to support the claims and context.

Research Gap Identification: the introduction identifies a research gap by highlighting that while research studies exist on the evaluation of LiaSR two component system and its association with CHX in S.mutans, less is known about the underlying mechanism. Although this is a clear and logical rationale for the study, more elaboration on the ‘underlying mechanism’ might make it clear.

Research Objectives: The introduction effectively conveys the primary research objectives, which are to investigate the impact of LiaSR system in S. mutans against CHX and proposed roles of efflux pump and CESRs in CHX resistance.

 

Hypothesis: The introduction does not mention any hypothesis.

Language and clarity: The introduction is generally clear, but it could benefit greatly from grammatical and syntactical adjustments for improved readability.

In summary, the introduction effectively sets the stage for the study by providing relevant background information, identifying research gaps, outlining the methodology, and stating clear research objectives. Incorporating more recent references and making language improvements would enhance the overall quality of the introduction.

Materials and methods: This section clearly states the methods used in the research work with great detail and clarity.

Overall, the "Materials and methods" section provides a clear and comprehensive description of the experimental procedures and analysis techniques used in the study.

Results: Authors could include the results from the 30mins in CHX treatment in figure 1b.

Discussion:

Limitations: the authors acknowledge the limitations of the study.  Firstly, the analysis primarily focuses on infrastructure, neglecting the quality of WASH services. Future studies should delve into service quality for a more nuanced understanding. Secondly, the omission of household member information limits the identification of reasons for low coverage. Conducting surveys with detailed member information could enhance the study's depth. Despite these limitations, the research provides valuable insights into regional characteristics, laying a foundation for tailored public health policies and highlighting the need for continued attention to the WASH sector.

 

Future directions and alternative approaches: The discussion touches upon potential future directions like studies on mechanistic studies on association between LiaSR and lmrB gene. Expanding on these possibilities and their significance would be beneficial.

Clarity and organization: The discussion is well-organized and logically structured, making it easy to follow the flow of ideas. However, some paragraphs are quite dense with information, and breaking them into smaller sections could improve readability.

Overall, the discussion effectively summarizes the study's findings, places them in context with related research, and provides insights into the potential implications of the results. Addressing the points mentioned above and providing more context regarding the clinical relevance of these findings would further enhance the discussion.

Conclusion: The conclusion is clear and concise, summarizing the findings without unnecessary elaboration. Overall, the conclusion effectively captures the main takeaways from the study and appropriately addresses the potential significance of the findings. This conclusion aligns well with the study's objectives and results. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

 

The manuscript titled "LiaSR two-component system regulates the resistance to chlorhexidine in Streptococcus mutans" concerns a very important aspect of bacterial resistance to antiseptic agents, most often causing infections in the oral cavity and dental areas. The authors planned the research very well and clearly presented the work methods. They used both classical and molecular methods. The discussion presented is logically thought out, and the conclusions drawn may constitute a valuable reference for future research.

Here are my minor comments:

- 2.1. Please explain whether the strains were purchased from a strain bank or obtained in some way

- Please describe more details about anaerobic cultivation (what device was used)

- Line 114: please enter the name of the centrifuge in brackets

- Line 117: please enter the name of the shaker in brackets

- 2.9 In this part the names RT-qPCR and qRT-PCR are used, please choose one and use it throughout the work

- 2.10 Please provide the p-value that was used for statistical analyses

- Lines 257-259 Please write the names of the bacteria correctly

 

 

Author Response

请参阅附件。

Author Response File: Author Response.pdf