Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Greetings,

The manuscript focuses on an important topic and provides multicenter epidemiological information on carbapenem-resistant Klebsiella spp. in Türkiye. The study is well organized and clinically relevant; however, several issues should be addressed before publication.

Major Comments

1. The sample size is relatively small (26 patients), which limits the generalizability of the findings and reduces the strength of the conclusions.

2. The study is primarily descriptive. No multivariable statistical analysis was performed to identify independent predictors associated with carbapenem-resistant Klebsiella spp.

3. A major limitation of the study is the lack of comprehensive molecular characterization. Carbapenem resistance mechanisms were investigated in only one isolate, preventing meaningful conclusions regarding the molecular epidemiology of resistance in Türkiye.

4. The manuscript reports a high ceftazidime-avibactam resistance rate (60%), but this finding is insufficiently discussed. Additional interpretation and comparison with recent regional and international studies are recommended.

5. No detailed comparison between participating centers was provided. Center-specific epidemiological differences, infection control practices, and resistance patterns would add significant value to the study.

6. The point-prevalence design provides only a single-day epidemiological snapshot and does not allow assessment of temporal trends in antimicrobial resistance.

Minor Comments

1. Several statements in the Introduction and Discussion rely on relatively old references (2014–2019). The manuscript would benefit from incorporating more recent literature (2023–2026), particularly regarding carbapenem-resistant Klebsiella spp., emerging resistance mechanisms, and current therapeutic options.

2. The manuscript should be carefully checked for scientific nomenclature. Bacterial genus and species names, including Klebsiella pneumoniae and Klebsiella spp., should be consistently formatted in italics throughout the manuscript, including the title, abstract, main text, tables, and figures.

3. More detailed information should be provided regarding antimicrobial susceptibility testing, including the exact number of isolates tested against each antimicrobial agent.

4. The Discussion section could be strengthened by comparing the reported prevalence rates with recent data from neighboring countries and other OXA-48-endemic regions.

Author Response

Reviewer 1

Comment 1

The sample size is relatively small (26 patients), limiting the generalizability and statistical power of the findings.

Response

We sincerely thank the Reviewer for this important comment. We agree that the relatively small sample size represents an inherent limitation of this multicenter point-prevalence study. Because the study was designed as a single-day nationwide point-prevalence survey, all eligible cases identified on the predefined survey day were included rather than a predetermined sample size. To address the Reviewer's concern, we substantially expanded the Limitations section of the Discussion. We now explicitly state that the study provides a contemporary multicenter epidemiological snapshot rather than definitive national prevalence estimates, acknowledge the limited statistical power and generalizability of the findings, and emphasize that larger prospective nationwide multicenter surveillance studies are required to validate our observations.

Changes made in the manuscript

• The Limitations section has been substantially expanded to discuss the implications of the point-prevalence design, the relatively small sample size, and the limited generalizability of the findings.
• Additional text emphasizing the need for larger prospective multicenter surveillance studies has been incorporated into the Discussion.

Reviewer 1 – Comment 2

The study is essentially descriptive. No multivariable statistical analysis was performed to identify independent determinants associated with carbapenem-resistant Klebsiella spp.

Response

We sincerely thank the Reviewer for this valuable comment. We agree that multivariable analyses can provide important insights into independent determinants of antimicrobial resistance when an appropriate study design and sample size are available. However, the present study was designed as a multicenter point-prevalence survey with a descriptive epidemiological objective rather than an analytical study. In addition, the relatively small number of included patients and the absence of a comparator group of patients without carbapenem-resistant Klebsiella spp. precluded meaningful multivariable analyses. To address the Reviewer's concern, we have expanded the Discussion section to explicitly clarify that the findings should be interpreted as descriptive epidemiological observations rather than evidence of causal associations. We also emphasize that future case-control or prospective cohort studies including appropriate comparator populations are needed to identify independent risk factors associated with carbapenem-resistant Klebsiella spp. acquisition and infection.

Changes made in the manuscript

• The Discussion section has been revised to clarify the descriptive nature of the study.
• A new paragraph has been added explaining why multivariable analyses were not methodologically appropriate and recommending future analytical studies with appropriate comparator groups.

 

Reviewer 1 – Comment 3

One of the major limitations of the study is the lack of comprehensive molecular characterization. Carbapenem resistance mechanisms were investigated in only one isolate, preventing meaningful conclusions regarding the molecular epidemiology of resistance in Türkiye.

Response

We thank the Reviewer for this important observation. We fully acknowledge that the limited availability of molecular characterization represents one of the major limitations of our study. Since this investigation was designed as a multicenter point-prevalence survey reflecting routine clinical practice, comprehensive molecular testing was not routinely available across all participating centers during the study period. Accordingly, systematic molecular characterization could not be performed for all isolates. To address this limitation, we substantially revised the Discussion by emphasizing that the present study primarily describes the clinical and epidemiological characteristics of carbapenem-resistant Klebsiella spp. rather than their molecular epidemiology. We further expanded the Discussion by highlighting the need for future nationwide multicenter surveillance studies incorporating standardized molecular testing to better define carbapenemase distribution and resistance mechanisms in Türkiye.

Changes made in the manuscript

• The limitations related to molecular characterization have been substantially expanded in the Discussion.
• Additional text has been included to explain the lack of routine molecular testing across participating centers.
• The need for future nationwide surveillance studies incorporating standardized molecular methods has been emphasized.

 

Reviewer 1 – Comment 4

The manuscript reports a high ceftazidime-avibactam resistance rate (60%), but this finding is insufficiently discussed. Additional interpretation and comparison with recent regional and international studies are recommended.

Response

We sincerely thank the Reviewer for this constructive suggestion. We agree that the initially submitted manuscript did not sufficiently discuss the observed ceftazidime-avibactam resistance rate. Accordingly, the Discussion section has been substantially expanded. We now provide a detailed interpretation of the observed resistance rate, emphasizing that susceptibility testing was available for only 20 isolates and that the findings should therefore be interpreted with caution. We also discuss the limited implementation of routine ceftazidime-avibactam susceptibility testing across participating centers during the study period. Furthermore, we incorporated several recent regional and international studies, including reports from Türkiye and multinational genomic surveillance studies from OXA-48-endemic regions, to place our findings into an appropriate epidemiological context. Finally, we emphasize the importance of routine susceptibility testing, molecular surveillance, and antimicrobial stewardship to preserve the clinical utility of ceftazidime-avibactam.

Changes made in the manuscript

• The Discussion regarding ceftazidime-avibactam resistance has been extensively expanded.
• Recent regional and international studies (2024–2025) have been incorporated.
• The limited number of tested isolates and the lack of comprehensive molecular characterization have been explicitly acknowledged when interpreting the resistance rate.

 

Reviewer 1 – Comment 5

A detailed comparison among the participating centers is lacking. Center-specific epidemiological differences, infection control practices, and resistance patterns would add significant value to the study.

Response

We sincerely thank the Reviewer for this valuable suggestion. In response, we have substantially expanded the hospital-level analysis by adding a new Table 7, which summarizes the characteristics of all participating centers, including hospital capacity, microbiological workload, prevalence of carbapenem-resistant Klebsiella spp., routine CRE screening policies, isolation practices, and antimicrobial stewardship program implementation. We also added a new paragraph to the Results section describing the variability observed among participating centers. However, because only two to six cases were identified at each hospital during the predefined survey day, meaningful statistical comparisons between centers were not methodologically feasible. This limitation has now been explicitly acknowledged in both the Results and Discussion sections.

Changes made in the manuscript

• A new Table 7 summarizing hospital-level characteristics and infection prevention practices has been added.
• A corresponding paragraph describing inter-hospital variability has been incorporated into the Results section.
• The Discussion now explains why statistical comparisons between centers were not appropriate because of the limited number of cases identified at each institution.

Reviewer 1 – Comment 6

The point-prevalence design provides only a single-day epidemiological snapshot and does not allow assessment of temporal trends in antimicrobial resistance.

Response

We thank the Reviewer for this important observation. We fully agree that a point-prevalence survey provides only a cross-sectional assessment and cannot evaluate temporal changes in antimicrobial resistance. To address this comment, we expanded the Discussion by explicitly emphasizing this methodological limitation. At the same time, we highlight that point-prevalence surveys remain a standardized and pragmatic approach for multicenter surveillance, allowing comparisons across institutions while providing valuable baseline epidemiological information. We also emphasize that future longitudinal multicenter surveillance studies are required to evaluate temporal trends in antimicrobial resistance.

Changes made in the manuscript

• The limitations related to the cross-sectional point-prevalence design have been expanded in the Discussion.
• Additional text emphasizing the need for longitudinal surveillance studies has been added.

Reviewer 1 – Minor Comment 1

Some statements in the Introduction and Discussion rely on relatively old references (2014–2019). The manuscript would benefit from incorporating more recent literature (2023–2026).

Response

We sincerely thank the Reviewer for this valuable suggestion. We have comprehensively updated the literature throughout the manuscript. Recent international guidelines, surveillance reports, and original research articles published between 2024 and 2026 have been incorporated into both the Introduction and Discussion. These include the WHO 2024 Bacterial Priority Pathogens List, ECDC 2025 surveillance data, and several recent studies addressing carbapenem-resistant Klebsiella spp., ceftazidime-avibactam resistance, molecular epidemiology, and contemporary treatment strategies. These additions strengthen the scientific background and improve the discussion of our findings within the context of current evidence.

Changes made in the manuscript

• The Introduction and Discussion sections have been extensively updated with recent literature published between 2024 and 2026.
• Several outdated references were replaced or complemented with more recent evidence.

 

Reviewer 1 – Minor Comment 2

Scientific nomenclature should be checked carefully. Bacterial genus and species names should be consistently italicized throughout the manuscript.

Response

We thank the Reviewer for this careful observation. The manuscript has been thoroughly reviewed, and the scientific nomenclature has been standardized throughout the text. Genus and species names, including Klebsiella pneumoniae and Klebsiella spp., have been consistently italicized in the title, abstract, main text, tables, and figure legends in accordance with scientific writing conventions.

Changes made in the manuscript

• Scientific nomenclature has been standardized throughout the manuscript, and all bacterial genus and species names have been consistently italicized.

 

Reviewer 1 – Minor Comment 3

More detailed information regarding antimicrobial susceptibility testing should be provided, including the exact number of isolates tested against each antimicrobial agent.

Response

We appreciate the Reviewer's helpful comment. In response, we substantially revised the Materials and Methods and Results sections by providing detailed information regarding microbiological identification, antimicrobial susceptibility testing methods, interpretive criteria (EUCAST 2026), and multidrug resistance (MDR) definitions. We also clarified the number of isolates tested for specific antimicrobial agents. Specifically, colistin susceptibility results were available for 17 isolates, whereas ceftazidime-avibactam susceptibility results were available for 20 isolates, and these numbers are now explicitly reported in the Results section.

Changes made in the manuscript

• Detailed microbiological methods have been added to the Materials and Methods section.
• The Results section now specifies the number of isolates tested for colistin and ceftazidime-avibactam susceptibility.

 

Reviewer 1 – Minor Comment 4

The Discussion could be strengthened by comparing the reported prevalence with contemporary data from neighboring countries and other OXA-48-endemic regions.

Response

We thank the Reviewer for this excellent suggestion. The Discussion has been expanded to place our findings in a broader regional and international context. We incorporated recent publications from Türkiye and multinational studies from OXA-48-endemic regions of Southern Europe, highlighting regional differences in carbapenemase epidemiology and their potential influence on antimicrobial susceptibility patterns, particularly for ceftazidime-avibactam. These additions provide a more comprehensive interpretation of our findings and improve the international relevance of the manuscript.

Changes made in the manuscript

• The Discussion now includes comparisons with recent studies from Türkiye and other OXA-48-endemic regions.
• Additional references have been incorporated to strengthen the international context of the findings.

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript presents a multicenter point-prevalence survey of carbapenem-resistant Klebsiella spp. across tertiary hospitals in Türkiye. The topic is clinically relevant; however, substantial methodological, epidemiological, microbiological, and reporting limitations reduce the scientific impact. Major concerns include unclear prevalence calculations, inadequate microbiological characterization, small sample size, inconsistent reporting, and limited statistical analyses.

Concerning issues

1. Critical information regarding bacterial identification, antimicrobial susceptibility testing methods, and interpretive criteria (CLSI/EUCAST) is missing, making the results difficult to evaluate and reproduce.
2. Despite focusing on carbapenem-resistant Klebsiella, resistance mechanisms were investigated in only one isolate, substantially limiting the scientific value of the study.
3. The sample size is too small to support meaningful epidemiological conclusions.
4. The denominators used for prevalence estimation are unclear and may not accurately reflect the burden of carbapenem-resistant Klebsiella in the participating hospitals.
5. Most observations, including associations with healthcare exposure, invasive devices, and prior antibiotic use, are already well established in the literature.
6. The manuscript relies solely on descriptive statistics without investigating risk factors or conducting comparative analyses that could generate meaningful epidemiological insights.
7. The manuscript discusses resistance epidemiology and infection control implications extensively, yet the limited microbiological and molecular data do not adequately support these conclusions.

 

Author Response

Reviewer 2

Comment 1

Critical information regarding bacterial identification, antimicrobial susceptibility testing methods, and interpretive criteria (CLSI/EUCAST) is missing, making the results difficult to evaluate and reproduce.

Response

We sincerely thank the Reviewer for this important comment. We fully agree that a detailed description of microbiological methods is essential for reproducibility and interpretation of the findings. Accordingly, we substantially revised the Microbiological Evaluation subsection of the Materials and Methods. The revised manuscript now includes detailed information regarding species identification methods (MALDI-TOF MS, VITEK® 2, and BD Phoenix 100 M50), antimicrobial susceptibility testing methods used across participating centers, colistin susceptibility testing, ceftazidime-avibactam susceptibility testing, interpretation according to EUCAST 2026 clinical breakpoints, and the definition of multidrug resistance (MDR) according to Magiorakos et al. These additions provide a more comprehensive description of the laboratory methodology used in the study.

Changes made in the manuscript

• The Microbiological Evaluation section has been substantially expanded.
• Species identification systems, antimicrobial susceptibility testing methods, EUCAST 2026 interpretive criteria, and the MDR definition have been added.

Comment 2

Although the study focuses on carbapenem-resistant Klebsiella, resistance mechanisms were investigated in only one isolate, substantially limiting the scientific value of the study.

Response

We thank the Reviewer for this valuable observation. We acknowledge that the limited availability of molecular characterization represents an important limitation of the study. Because this multicenter survey reflects routine clinical practice, comprehensive carbapenemase genotyping was not routinely available across all participating centers during the study period. Therefore, systematic molecular characterization could not be performed for all isolates. We have revised the Discussion to clearly acknowledge this limitation and to emphasize that the primary objective of the present study was to describe the epidemiological and clinical characteristics of carbapenem-resistant Klebsiella spp. rather than their molecular epidemiology. We further highlight the need for future nationwide multicenter studies incorporating standardized molecular testing.

 

Changes made in the manuscript

• The Discussion has been expanded to better acknowledge the limited molecular characterization.
• Future multicenter studies including standardized molecular testing have been recommended.

Comment 3

The sample size is too small to draw meaningful epidemiological conclusions.

Response

We appreciate the Reviewer's comment. We recognize that the relatively small sample size limits the statistical power and generalizability of the findings. However, this reflects the inherent nature of a multicenter point-prevalence survey, in which all eligible patients identified on a predefined survey day are included rather than a predetermined sample size. We have clarified this point in the Discussion and emphasized that the results should be interpreted as descriptive multicenter epidemiological observations rather than definitive national estimates. We also recommend larger prospective multicenter surveillance studies to validate these findings.

Changes made in the manuscript

• The limitations related to sample size and generalizability have been expanded in the Discussion.
• The descriptive nature of the study has been emphasized.

Comment 4

The denominator used for prevalence estimates is unclear and may not accurately reflect the burden of carbapenem-resistant Klebsiella in the participating hospitals.

Response

We sincerely thank the Reviewer for this constructive comment. To improve clarity, we expanded the Discussion by explaining the rationale for the prevalence calculations used in the study. We now explicitly state that prevalence was calculated using two complementary denominators (all microbiological cultures obtained on the survey day and culture-positive specimens). We further clarify that these measures should be interpreted as descriptive indicators of microbiological burden rather than patient-level prevalence estimates, and we discuss the strengths and limitations of each denominator.

Changes made in the manuscript

• The Discussion has been revised to explain the prevalence calculations and the interpretation of both denominators.
• Additional clarification regarding the epidemiological meaning of the reported prevalence estimates has been included.

Comment 5

Most observations, including healthcare exposure, invasive devices, and previous antibiotic use, have already been well documented in the literature.

Response

We thank the Reviewer for this thoughtful comment. We agree that these clinical characteristics have been described previously. However, the objective of the present study was not to establish novel risk factors but rather to provide contemporary multicenter epidemiological data describing the current characteristics of patients with carbapenem-resistant Klebsiella spp. across tertiary-care hospitals in different geographical regions of Türkiye. To better reflect this objective, we revised both the Introduction and the Discussion to emphasize the descriptive epidemiological nature of the study and its contribution to current national surveillance data.

Changes made in the manuscript

• The study objectives have been clarified in the Introduction.
• The Discussion has been revised to better emphasize the descriptive epidemiological contribution of the study.

Comment 6

The manuscript relies only on descriptive statistics without investigating risk factors or performing comparative analyses capable of generating meaningful epidemiological insights.

Response

We appreciate the Reviewer's comment. We agree that analytical studies investigating independent risk factors provide complementary evidence. However, because the present investigation was designed as a multicenter point-prevalence study without a comparator group, comparative analyses and multivariable risk factor analyses were not methodologically appropriate. To address this concern, we explicitly state this limitation in the revised Discussion and recommend future case-control and prospective cohort studies designed to identify independent determinants of carbapenem-resistant Klebsiella spp. acquisition and infection.

Changes made in the manuscript

• The methodological limitations regarding the absence of comparative analyses have been explicitly described.
• Recommendations for future analytical studies have been added.

 

Comment 7

The implications regarding resistance epidemiology and infection control are discussed extensively, although the limited microbiological and molecular data do not sufficiently support these conclusions.

Response

We sincerely thank the Reviewer for this important observation. We carefully revised the Discussion to ensure that the conclusions are fully supported by the available data. Statements regarding molecular epidemiology have been moderated, and greater emphasis has been placed on the descriptive clinical and epidemiological findings of the study. We also strengthened the Limitations section by explicitly acknowledging the restricted molecular characterization and recommending future studies incorporating comprehensive molecular analyses. Finally, the Discussion was expanded with additional contemporary literature to provide a balanced interpretation of our findings within the context of existing evidence.

Changes made in the manuscript

• The Discussion has been revised to provide a more balanced interpretation of the findings.
• The limitations regarding microbiological and molecular data have been strengthened.
• Additional recent references have been incorporated to support the discussion.

 

Reviewer 3 Report

Comments and Suggestions for Authors

An epidemiological study presenting the results of a point-prevalence survey of carbapenem-resistant Klebsiella spp. conducted in seven tertiary care hospitals located across four regions of Turkey.

I have a question regarding the criteria used to select these particular hospitals and, more broadly, these specific regions.

On 19 February 2026, carbapenem-resistant Klebsiella spp. was isolated from 26 patients. The authors provided the clinical characteristics of these patients, including the type of clinical specimen from which the strains were isolated, the type of infection, and the use of medical devices during treatment.

One limitation of the study is the lack of information on whether these isolates were multidrug-resistant (MDR) and what their antimicrobial susceptibility profiles were.

Another limitation is that the isolates were not identified to the species level. Moreover, the authors do not describe the identification method, such as VITEK or MALDI-TOF MS.

The most significant limitation of the study is the absence of molecular characterization of carbapenem resistance. With the exception of one isolate, the presence of carbapenemase-encoding genes, including blaOXA-48, blaVIM, blaKPC, and blaNDM, was not investigated, as acknowledged by the authors.

Minor comment: the sentence in lines 49–51 requires clarification, as its meaning is not entirely clear.

Author Response

Reviewer 3

Comment 1

I have a question regarding the criteria used for selecting these hospitals and, more generally, these geographical regions.

Response

We sincerely thank the Reviewer for this important comment. To clarify the selection process of the participating hospitals, we have revised the Study Design subsection of the Materials and Methods. We now explicitly state that the participating hospitals were selected based on their willingness to participate, the availability of infectious diseases specialists responsible for local data collection, and their representation of different geographical regions of Türkiye. This information has been added to improve the transparency of the study design.

Changes made in the manuscript

• The Study Design subsection has been revised to clearly describe the hospital selection criteria.
• The following sentence has been added:

"Participating hospitals were selected on the basis of their willingness to participate, availability of infectious diseases specialists responsible for local data collection, and representation of different geographical regions of Türkiye."

Comment 2

One limitation of the study is the lack of information regarding whether these isolates were multidrug-resistant (MDR) and what their antimicrobial susceptibility profiles were.

Response

We sincerely thank the Reviewer for this valuable suggestion. In response, we have substantially expanded both the Materials and Methods and Results sections. The revised manuscript now clearly states that multidrug resistance (MDR) was defined according to the international criteria proposed by Magiorakos et al. Furthermore, antimicrobial susceptibility results are now reported in greater detail, including the number of isolates tested for colistin and ceftazidime-avibactam and the corresponding resistance rates. These additions provide a more comprehensive description of the microbiological characteristics of the isolates.

Changes made in the manuscript

• The MDR definition has been added to the Materials and Methods.
• The Results section now reports the number of isolates tested for colistin and ceftazidime-avibactam and their resistance rates.

Comment 3

Another limitation is that the isolates were not identified at the species level. Furthermore, the authors did not describe the identification method, such as VITEK or MALDI-TOF MS.

Response

We thank the Reviewer for this constructive comment. To improve methodological transparency, we substantially revised the Microbiological Evaluation subsection. The revised manuscript now describes the microbiological identification systems routinely used across the participating centers, including MALDI-TOF MS, VITEK® 2, and BD Phoenix 100 M50. We also expanded the description of antimicrobial susceptibility testing methods and interpretation according to EUCAST 2026 clinical breakpoints. In addition, species identification has been clarified wherever such information was available.

Changes made in the manuscript

• Detailed microbiological identification methods have been added to the Materials and Methods.
• Information regarding antimicrobial susceptibility testing methods and EUCAST 2026 interpretation criteria has been incorporated.

Comment 4

The major limitation is the lack of molecular characterization of carbapenem resistance. Except for one isolate, carbapenemase genes (blaOXA-48, blaVIM, blaKPC and blaNDM) were not investigated.

Response

We appreciate the Reviewer's important observation. We fully acknowledge that the lack of comprehensive molecular characterization is one of the major limitations of the present study. Because this investigation was conducted as a multicenter point-prevalence survey reflecting routine clinical practice, molecular testing was not routinely available at all participating centers during the study period. We have therefore strengthened the Discussion by explicitly acknowledging this limitation and by emphasizing that future nationwide multicenter surveillance studies incorporating standardized molecular characterization are necessary to better define the molecular epidemiology and resistance mechanisms of carbapenem-resistant Klebsiella spp. in Türkiye.

Changes made in the manuscript

• The limitations related to molecular characterization have been expanded in the Discussion.
• Future nationwide studies including standardized molecular testing have been recommended.

Comment 5

Minor comment: The sentence in lines 49–51 is not entirely clear and requires clarification.

Response

We thank the Reviewer for pointing this out. The relevant sentence in the Introduction has been revised to improve clarity and readability. The revised text more clearly explains the clinical importance of carbapenem-resistant Klebsiella spp. and the rationale for the present study.

Changes made in the manuscript

• The unclear sentence in the Introduction has been rewritten for improved clarity and scientific readability.

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Good work.

Author Response

Comment: Good work

Responce: We sincerely thank the reviewer for the careful evaluation of our manuscript and for the positive and encouraging comments. We greatly appreciate the reviewer's assessment that the manuscript is scientifically sound, clearly presented, and written in appropriate English. We are pleased that the reviewer found the study to be of interest and considered the manuscript suitable in its original form. As no specific revisions were requested, no changes were made to the manuscript in response to Reviewer 1.

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Multicenter Point-Prevalence Study of Carbapenem-Resistant Klebsiella spp. in Türkiye: Epidemiology, Antimicrobial Resistance, and Infection Control Practices

The manuscript addresses an important antimicrobial resistance issue and provides useful descriptive epidemiological data from multiple Turkish centers. However, substantial revisions are required to improve its scientific value.

Line 45, 62: Should be Klebsiella spp.

I found non-italic for genes and scientific name throughout the manuscript. Revise it appropriately.

Introduction

Lines 66–70: Among the 2024 WHO priority pathogen list, CRKP is not the highest priority pathogens, In Critical priority list its not included, Please restate your statement. It may be one of the top priority listed pathogens.

Lines 76–88: The introduction shifts repeatedly between: Enterobacterales, carbapenem-resistant Enterobacterales (CRE), CRKP, carbapenem-resistant Klebsiella spp. These terms should be consistently defined.

The authors claim nationwide multicenter data are lacking, although the study only includes seven tertiary hospitals selected by convenience sampling. Therefore, the term "nationwide" should be avoided.

The introduction needs some relevant references. Follow these. https://doi.org/10.1186/s40550-026-00147-z , https://doi.org/10.2166/wh.2026.075

Results

IQR of 2.8–48.3 days. The lower quartile of 2.8 days appears unusually low for CRKP-positive hospitalized patients and Verify this.

Include confidence intervals for all major resistance estimates.

Lines 131

UTI prevalence is reported as 53.4%, whereas 14/26 equals 53.8%. Check appropriately.

Table 3: I observed a miss match among the number of samples. The sum of the samples are 28. But you divide the numerator by 26. So, clarify this inconsistent issues.

 

Lines 147–148: The manuscript states that CR Klebsiella spp. were considered causative pathogens in 24 patients, but only 21 cases were healthcare-associated infections. Its unclear.

Lines 151–152: Only one isolate underwent molecular testing. Include this as limitations.

Lines 169–170: Prevalence was calculated using cultures rather than patients. It’s misleading.   It should be "Isolation frequency" or "culture-based prevalence."

Discussion

Discussion occasionally repeats introductory material.

In some of the section needs appropriate citations.

Materials and Methods

Lines 388: Inclusion criteria are problematic: hospitalized adults on study day; patients with cultures positive on the same day. These represent two different sampling frames.

Lines 415: One center used colistin E-test despite EUCAST recommendations discouraging gradient diffusion methods for colistin susceptibility testing. This is a major technical issue.

 

Author Response

We sincerely thank the reviewer for the careful evaluation of our manuscript and for the constructive comments. We greatly appreciate the time and effort devoted to reviewing our work. We have carefully considered all comments and revised the manuscript accordingly. The major revisions include clarification of the study design and inclusion criteria, standardization of terminology, revision of prevalence terminology to culture-based prevalence, addition of confidence intervals for major resistance estimates, clarification of healthcare-associated infection definitions, expansion of the limitations section, and revision of the Discussion to improve clarity and scientific accuracy. We believe that these revisions have strengthened the manuscript. Detailed point-by-point responses are provided below.

Comment 1

Reviewer: Line 45, 62: Should be Klebsiella spp.

Response: We thank the reviewer for this valuable comment. The terminology has been revised throughout the manuscript. The term Klebsiella spp. is now used consistently when referring to the isolates included in the present study. Species-specific terminology (Klebsiella pneumoniae) has been retained only when referring to published studies, established classifications, or studies specifically investigating that species.

Comment 2

Reviewer: I found non-italic for genes and scientific name throughout the manuscript. Revise it appropriately.

Response: We thank the reviewer for this careful observation. The entire manuscript has been thoroughly reviewed, and all scientific names and gene names have been formatted consistently in accordance with the journal's style requirements.

Comment 3

Reviewer: Among the 2024 WHO priority pathogen list, CRKP is not the highest priority pathogen. In the Critical priority list it is not included. Please restate your statement. It may be one of the top priority listed pathogens.

Response: We thank the reviewer for identifying this inaccuracy. The relevant statement has been revised to accurately reflect the 2024 WHO Bacterial Priority Pathogens List. The revised text no longer implies that carbapenem-resistant Klebsiella pneumoniae is the highest-priority pathogen and is now fully consistent with the current WHO classification.

Comment 4

Reviewer: Lines 76–88: The introduction shifts repeatedly between Enterobacterales, carbapenem-resistant Enterobacterales (CRE), CRKP, carbapenem-resistant Klebsiella spp. These terms should be consistently defined.

Response: We thank the reviewer for this important comment. The terminology has been carefully reviewed and standardized throughout the manuscript. The term carbapenem-resistant Klebsiella spp. is now used consistently when referring to the isolates included in the present study. Broader taxonomic terms, such as carbapenem-resistant Enterobacterales (CRE), and species-specific terminology (Klebsiella pneumoniae) have been retained only when referring to published literature, established classifications, or studies specifically addressing those organisms.

Comment 5

Reviewer: The authors claim nationwide multicenter data are lacking, although the study only includes seven tertiary hospitals selected by convenience sampling. Therefore, the term "nationwide" should be avoided.

Response: We thank the reviewer for this valuable suggestion. We agree that the term "nationwide" could be interpreted as implying a nationally representative sample. Therefore, the wording has been revised throughout the manuscript to more accurately describe the study as a multicenter point-prevalence study conducted in seven tertiary-care hospitals located in different geographical regions of Türkiye.

Comment 6

Reviewer: The introduction needs some relevant references. Follow these...

Response: We thank the reviewer for the suggested references. We carefully evaluated both publications. However, as these studies primarily focus on antimicrobial resistance in foodborne and environmental isolates rather than the clinical epidemiology of carbapenem-resistant Klebsiella spp. in hospitalized patients, we believe that they are not directly relevant to the objectives and scope of the present study. Therefore, they were not incorporated into the revised manuscript.

Comment 7

Reviewer: IQR of 2.8–48.3 days. The lower quartile of 2.8 days appears unusually low for CRKP-positive hospitalized patients. Verify this.

Response: We thank the reviewer for this careful observation. We rechecked the original dataset and confirmed that the reported interquartile range (2.8–48.3 days) is correct. Length of hospital stay was calculated as the interval between the date of hospital admission and the study day (February 19, 2026). Therefore, no changes were required.

Comment 8

Reviewer: UTI prevalence is reported as 53.4%, whereas 14/26 equals 53.8%. Check appropriately.

Response: We thank the reviewer for identifying this calculation error. The percentage has been corrected from 53.4% to 53.8% in the revised manuscript.

 Comment 9

Reviewer: Table 3: I observed a mismatch among the number of samples. The sum of the samples are 28. But you divide the numerator by 26. So, clarify this inconsistent issue.

Response: We thank the reviewer for this important comment. The unit of analysis in our study was the patient rather than the individual specimen. Although 28 clinical specimens were obtained, these originated from 26 patients because two patients contributed specimens from two different anatomical sites. Accordingly, the percentages presented in Table 3 were calculated using the number of patients (n = 26).To improve clarity and avoid misunderstanding, we have added a footnote to Table 3 explaining this point.

Comment 10

Reviewer: Lines 147–148: The manuscript states that CR Klebsiella spp. were considered causative pathogens in 24 patients, but only 21 cases were healthcare-associated infections. It is unclear.

Response: We thank the reviewer for this important observation. We have clarified this point in the revised manuscript. Healthcare-associated infections were classified according to the predefined ECDC point-prevalence survey definitions. Although carbapenem-resistant Klebsiella spp. were considered the causative pathogens in 24 patients, only 21 cases fulfilled the ECDC criteria for healthcare-associated infection. The remaining three patients had positive cultures obtained on the day of hospital admission and therefore did not meet the predefined HAI criteria.

Comment 11

Reviewer: Only one isolate underwent molecular testing. Include this as limitations.

Response: We thank the reviewer for this valuable suggestion. This limitation has now been explicitly acknowledged in the Discussion section. We have clarified that molecular characterization was available for only one isolate, limiting assessment of the distribution of carbapenemase genes among the study isolates. We also emphasize the need for future multicenter surveillance studies incorporating standardized molecular testing.

Comment 12

Reviewer: Prevalence was calculated using cultures rather than patients. It is misleading. It should be "Isolation frequency" or "culture-based prevalence."

Response: We thank the reviewer for this valuable comment and agree that the original terminology could be misleading. Throughout the revised manuscript, the term "culture-based prevalence" has been adopted to accurately reflect that microbiological cultures were obtained only when clinically indicated rather than systematically from all hospitalized patients. In addition, we expanded the Discussion to explain this methodological consideration and to clarify the interpretation and limitations of these estimates.

 Comment 13

Reviewer: Discussion occasionally repeats introductory material.

Response: We thank the reviewer for this helpful suggestion. The Discussion has been carefully revised to improve its focus and avoid unnecessary repetition of introductory information. Several sections were condensed and restructured to emphasize interpretation of the study findings rather than background information, thereby improving the overall flow and readability of the Discussion.

Comment 14

Reviewer: In some sections needs appropriate citations.

Response: We thank the reviewer for this valuable comment. Additional relevant references have been incorporated into the Discussion where appropriate, particularly in sections addressing molecular epidemiology, antimicrobial resistance patterns, and recent findings from Türkiye, to better support our interpretations.

Comment 15

Reviewer: Lines 388: Inclusion criteria are problematic: hospitalized adults on study day; patients with cultures positive on the same day. These represent two different sampling frames.

Response: We thank the reviewer for highlighting this important point. The inclusion criteria have been revised to clarify the study design and avoid ambiguity regarding the sampling frame. The revised text explicitly states that all hospitalized adult patients present on the study day were screened and that only those with at least one culture yielding carbapenem-resistant Klebsiella spp. from specimens collected on the study day were included in the analysis. We believe that this revision more accurately reflects the study methodology.

Comment 16

Reviewer: One center used colistin E-test despite EUCAST recommendations discouraging gradient diffusion methods for colistin susceptibility testing. This is a major technical issue.

Response: We thank the reviewer for this important methodological comment. We agree that broth microdilution is the EUCAST-recommended reference method for colistin susceptibility testing. In one participating center, however, broth microdilution was not available during the study period, and colistin susceptibility testing was performed using the E-test as part of routine laboratory practice. Because the isolates were not preserved after completion of the point-prevalence survey, retrospective confirmatory broth microdilution testing was not feasible. To address this concern, we have explicitly acknowledged this issue as a limitation in the Discussion and emphasized that the reported colistin susceptibility results should be interpreted with caution.

We once again thank the Editor and the Reviewers for their valuable comments and suggestions, which have significantly improved the quality and clarity of our manuscript.

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

All of the concerns had been revised.