Correlation Between Carbapenemase-Producing Enterobacterales Load, Environmental Contamination, and Transmission in Critical Care Units (CPE-Load ICU S)

June 29, 2026 updated by: MARIA INES STANELONI, Hospital Italiano de Buenos Aires

Carbapenemase-producing Enterobacterales (CPE) are multidrug-resistant bacteria that can colonize the gastrointestinal tract of hospitalized patients and spread within intensive care units (ICUs). Some colonized individuals may carry a particularly high bacterial burden and contribute disproportionately to environmental contamination and transmission to other patients. Identifying these high-risk individuals could improve infection prevention and control strategies.

This prospective observational study will be conducted in the Adult Intensive Care Unit of Hospital Italiano de Buenos Aires. Patients identified as colonized with CPE through routine surveillance will undergo quantitative culture and real-time polymerase chain reaction (PCR) testing of rectal swabs to measure bacterial load. Environmental samples will also be collected from high-touch surfaces surrounding colonized patients. In selected cases, molecular typing methods will be used to evaluate genetic relatedness between patient and environmental isolates and to investigate possible transmission events.

The primary objective is to determine the correlation between bacterial load measured by culture and the PCR cycle threshold (Ct) value. Secondary objectives include evaluating the association between bacterial load and environmental contamination, and assessing whether patients with higher bacterial loads are more likely to contribute to transmission within the ICU. Results may help identify patients with increased dissemination potential and support targeted infection prevention interventions.

Study Overview

Status

Not yet recruiting

Conditions

Detailed Description

Carbapenemase-producing Enterobacterales (CPE) represent a major global public health threat because of their extensive antimicrobial resistance and their ability to spread within healthcare facilities. Gastrointestinal colonization is recognized as the main reservoir for transmission. Previous studies have suggested that a subset of colonized patients, often referred to as "super-spreaders," carry a substantially higher bacterial burden and may account for a disproportionate share of environmental contamination and transmission events.

Although bacterial load can be quantified using culture-based and molecular methods, there is currently no validated cycle threshold (Ct) value from routinely used real-time PCR assays that reliably identifies patients with high dissemination potential. Establishing a correlation between Ct values and bacterial burden could provide a practical and accessible tool for infection prevention programs.

This prospective observational cohort study will be conducted in the Adult Intensive Care Unit of Hospital Italiano de Buenos Aires. All patients identified through the institutional surveillance program as colonized with CPE will be eligible for inclusion. For each CPE-positive patient, rectal swabs obtained as part of routine surveillance will undergo quantitative culture on selective chromogenic media and molecular testing using real-time PCR targeting carbapenemase genes. Bacterial load will be estimated using colony-forming unit counts and PCR Ct values.

Environmental contamination will be assessed through systematic sampling of high-touch surfaces in the patient's surroundings, including bed linen, bedside furniture, and medical equipment. Environmental isolates will undergo microbiological and molecular characterization. In selected situations, whole genome sequencing or pulsed-field gel electrophoresis will be performed to evaluate genetic relatedness among isolates recovered from patients, environmental samples, and secondary cases.

The primary outcome is the correlation between quantitative bacterial load and PCR Ct values. Secondary outcomes include the extent of environmental contamination associated with different bacterial loads and the occurrence of transmission events involving genetically related strains. Multivariable analyses will evaluate the influence of relevant clinical and epidemiological factors, including length of stay, fecal incontinence, prior antimicrobial exposure, immunosuppression, and other potential confounders.

The study involves minimal risk because all patient samples are obtained within the framework of routine infection control surveillance. Findings from this study may improve the identification of patients with increased transmission potential and support more targeted and efficient infection prevention strategies in critical care settings.

Study Type

Observational

Enrollment (Estimated)

60

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Argentina
    • Buenos Aires F.D.
      • Buenos Aires, Buenos Aires F.D., Argentina, 1199
        • Hospital Italiano de Buenos Aires
        • Contact:
        • Contact:
        • Principal Investigator:
          • Maria Ines Staneloni, MD
        • Sub-Investigator:
          • Emilio Felipe Huaier Arriazu, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adult patients hospitalized in the Adult Intensive Care Unit of Hospital Italiano de Buenos Aires during the study period, with a positive surveillance rectal swab for carbapenemase-producing Enterobacterales detected through the institutional infection control surveillance program.

Description

Inclusion Criteria

  • Age 18 years or older.
  • Hospitalized in the Adult Intensive Care Unit of Hospital Italiano de Buenos Aires during the study period.
  • Positive surveillance rectal swab for carbapenemase-producing Enterobacterales.

Exclusion Criteria

-Patients colonized or infected with carbapenemase-producing Enterobacterales who remained in the same room for less than 48 hours.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
CPE-Colonized ICU Patients
Patients admitted to the Adult Intensive Care Unit of Hospital Italiano de Buenos Aires with a positive surveillance rectal swab for carbapenemase-producing Enterobacterales (CPE). Participants will undergo quantitative culture and real-time PCR testing of rectal swabs as part of routine surveillance. Environmental samples will be collected from high-touch surfaces surrounding colonized patients to evaluate environmental contamination and transmission dynamics.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation Between PCR Cycle Threshold (Ct) Value and Quantitative Bacterial Load (CFU/swab) in Rectal Surveillance Swabs
Time Frame: At baseline (time of positive rectal surveillance swab)
Spearman correlation coefficient between the cycle threshold (Ct) value obtained by real-time PCR (BD MAX™ system) targeting carbapenemase genes and the quantitative bacterial load measured by culture on CHROMagar™ KPC selective medium, expressed as colony-forming units per swab (CFU/swab), from rectal surveillance swabs positive for carbapenemase-producing Enterobacterales.
At baseline (time of positive rectal surveillance swab)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation Between Quantitative Bacterial Load (CFU/swab) in Rectal Swabs and Number of CPE-Positive High-Touch Environmental Surfaces
Time Frame: Within 24 hours of rectal swab collection
Spearman correlation coefficient between the quantitative bacterial load of carbapenemase-producing Enterobacterales in rectal surveillance swabs, measured by culture on CHROMagar™ KPC selective medium and expressed as colony-forming units per swab (CFU/swab), and the number of CPE-positive high-touch surfaces out of 5 sampled (bed linen, bedside table, and infusion pump), assessed by quantitative culture on CHROMagar™ KPC contact plates.
Within 24 hours of rectal swab collection
Correlation Between PCR Cycle Threshold (Ct) Value in Rectal Swabs and Number of CPE-Positive High-Touch Environmental Surfaces
Time Frame: Within 24 hours of rectal swab collection
Spearman correlation coefficient between the cycle threshold (Ct) value obtained by real-time PCR (BD MAX™ system) targeting carbapenemase genes from rectal surveillance swabs positive for carbapenemase-producing Enterobacterales, and the number of CPE-positive high-touch surfaces out of 5 sampled (bed linen, bedside table, and infusion pump), assessed by quantitative culture on CHROMagar™ KPC contact plates.
Within 24 hours of rectal swab collection
Correlation Between Quantitative Bacterial Load (CFU/swab) in Rectal Swabs and Total Colony-Forming Units Recovered from Environmental Surfaces
Time Frame: Within 24 hours of rectal swab collection
Spearman correlation coefficient between the quantitative bacterial load of carbapenemase-producing Enterobacterales in rectal surveillance swabs, measured by culture on CHROMagar™ KPC selective medium and expressed as colony-forming units per swab (CFU/swab), and the total colony-forming units (CFU) recovered across five high-touch surfaces (bed linen, bedside table, and infusion pump) surrounding colonized patients, assessed by quantitative culture on CHROMagar™ KPC contact plates.
Within 24 hours of rectal swab collection
Correlation Between PCR Cycle Threshold (Ct) Value in Rectal Swabs and Total Colony-Forming Units Recovered from Environmental Surfaces
Time Frame: Within 24 hours of rectal swab collection
Spearman correlation coefficient between the cycle threshold (Ct) value obtained by real-time PCR (BD MAX™ system) targeting carbapenemase genes from rectal surveillance swabs positive for carbapenemase-producing Enterobacterales, and the total colony-forming units (CFU) recovered across five high-touch surfaces (bed linen, bedside table, and infusion pump) surrounding colonized patients, assessed by quantitative culture on CHROMagar™ KPC contact plates.
Within 24 hours of rectal swab collection
Number of Index Patients with Transmission of at Least One Genetically Related CPE Strain to a Co-Hospitalized Patient
Time Frame: Up to 6 months
Number of index patients associated with at least one secondary case carrying a genetically related carbapenemase-producing Enterobacterales strain, confirmed by whole genome sequencing (WGS) and/or pulsed-field gel electrophoresis (PFGE), among patients hospitalized in the same intensive care unit during the study period.
Up to 6 months
Number of Patients Meeting Predefined Criteria for Super-Spreader Classification
Time Frame: At baseline (time of CPE detection and environmental sampling)
Number of CPE-colonized patients classified as potential super-spreaders, defined post-hoc as having a cycle threshold (Ct) value below the 25th percentile of the study population and at least 2 positive environmental surfaces with more than 50 colony-forming units (CFU) each, assessed by quantitative culture on CHROMagar™ KPC contact plates.
At baseline (time of CPE detection and environmental sampling)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hospital Italiano de Buenos Aires

Collaborators

National Council of Scientific and Technical Research, Argentina

Investigators

  • Principal Investigator: Maria Ines Staneloni, MD, Hospital Italiano de Buenos Aires

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

August 1, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

January 15, 2027

Study Registration Dates

First Submitted

June 9, 2026

First Submitted That Met QC Criteria

June 29, 2026

First Posted (Actual)

July 6, 2026

Study Record Updates

Last Update Posted (Actual)

July 6, 2026

Last Update Submitted That Met QC Criteria

June 29, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 7703 (CTEP)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Individual participant data underlying the results reported in publications will be available after de-identification. Data may be shared with qualified researchers upon reasonable request to the principal investigator and after approval by the Hospital Italiano de Buenos Aires Ethics Committee, in accordance with institutional policies and applicable regulations regarding data protection and patient confidentiality.

What IPD Will Be Shared? De-identified demographic data Clinical characteristics Rectal swab quantitative culture results PCR cycle threshold (Ct) values Environmental sampling results Molecular characterization and genomic data used in analyses Derived study variables

IPD Sharing Time Frame

Beginning 6 months after publication and ending 5 years after publication.

IPD Sharing Access Criteria

Researchers who provide a methodologically sound proposal may access de-identified participant data for scientific purposes. Requests will be reviewed by the principal investigator and the institutional ethics committee. Data sharing agreements may be required before data release.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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