Effect of Direct-from-blood Bacterial Testing on Antibiotic Administration and Clinical Outcomes

February 23, 2026 updated by: Matthew Semler, Vanderbilt University Medical Center

Effect of Direct-from-blood Bacterial Testing on Antibiotic Administration and Clinical Outcomes: A Learning Healthcare Pragmatic Randomized Trial

Bacterial blood stream infections are common and life-threatening. Bloodstream infections have historically been identified using blood cultures, which often take 24-72 hours to result and are imperfectly sensitive. Early administration of antimicrobial therapy is a fundamental component of the management of adults presenting to the hospital with a suspected bloodstream infection and/or sepsis.

But because blood cultures frequently take 24-72 hours to result, patients are typically treated with empiric, broad spectrum antibiotics. In a meta-analysis of sepsis studies, empirical antibiotic therapy was inappropriate for the organism that ultimately grew in culture in almost half of patients. Thus, patients are commonly exposed to unnecessary antibiotics without evidence of infection or with evidence of infection requiring narrow antibiotic selection. For example, current guidelines recommend the use of empiric intravenous vancomycin as coverage for a bloodstream infection caused by the bacterial pathogen methicillin-resistant S. aureus (MRSA). Vancomycin requires careful monitoring due to its narrow therapeutic range and high risk of toxicity. Administration of vancomycin to patients who do not have MRSA can lead to avoidable adverse drug events and costs, as well as drive antimicrobial resistance.

There has been increasing interest in using rapid diagnostic tests that identify bacteria directly from whole blood samples without relying on growth in culture, referred to as "direct-from-blood" tests, to guide early therapeutic management of patients with suspected bloodstream infections in addition to standard blood cultures. One such FDA-approved, direct-from-blood test is the T2Bacteria® Panel. This panel's performance as a direct-from blood test for bacterial pathogens has been described in previous studies. A recent meta-analysis of largely observational studies reported a faster transition to targeted microbial therapy and de-escalation of empirical microbial therapy, as well as a shorter duration of intensive care unit stay and hospital stay for patients who received this direct-from-blood test.

We will conduct a pragmatic, randomized clinical trial examining the effect of using the T2Bacteria® Panel direct from-blood testing, compared to using blood cultures alone (standard of care), on antimicrobial receipt and clinical outcomes for adults presenting to the hospital with suspected infection and who have been initiated on empiric therapy with intravenous vancomycin.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

500

Phase

  • Not Applicable

Contacts and Locations

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

Study Locations

  • United States
    • Tennessee
      • Nashville, Tennessee, United States, 37203
        • Vanderbilt University Medical Center

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

Description

Inclusion Criteria:

  • Patient is located in the Emergency Department at Vanderbilt University Hospital
  • ≤ 12 hours from patient presentation to the Emergency Department at Vanderbilt University Hospital
  • Age ≥ 18 years
  • Clinician has ordered blood cultures
  • Clinician has ordered intravenous vancomycin

Exclusion Criteria:

  • Patient is known to be a prisoner
  • Patient is known to be pregnant
  • Patient is known to have received 2 or more doses of vancomycin since presentation to the Vanderbilt ED
  • Patient is known to have a positive bacterial culture in the previous 7 days
  • Patient is known to have an infection for which at least 7 days of intravenous vancomycin would routinely be administered regardless of bacterial testing results (e.g., skin and soft tissue infection, etc.)

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

  • Primary Purpose: Health Services Research
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Usual Care
Patients will receive blood cultures and will not receive direct-from-blood testing.
Other: Usual Care
Standard blood cultures.
Active Comparator: Direct-from-blood testing
In addition to usual care, patients will receive direct-from-blood testing using the T2Bacteria® Panel.
Other: T2Bacteria® Panel (direct-from-blood testing)
Providers will be prompted to order the T2Bacteria® Panel (direct-from-blood testing) and accompanying communications regarding panel results will be delivered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time to Last Dose of Intravenous Vancomycin
Time Frame: Baseline to 14 days
The time between randomization and the start time for the last dose of intravenous vancomycin received by the patient within 14 days of randomization.
Baseline to 14 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time to Last Dose of Systemic Anti-pseudomonal Beta-lactam Antibiotic
Time Frame: Baseline to 14 days
The time between randomization and start time of the last dose of systemic anti-pseudomonal beta-lactam antibiotic received by the patient within 14 days of randomization.
Baseline to 14 days

Collaborators and Investigators

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

Sponsor

Vanderbilt University Medical Center

Investigators

  • Principal Investigator: Matthew Semler, MD, MSc, Vanderbilt University Medical Center

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 (Actual)

December 13, 2023

Primary Completion (Actual)

December 14, 2024

Study Completion (Actual)

April 22, 2025

Study Registration Dates

First Submitted

September 28, 2023

First Submitted That Met QC Criteria

September 28, 2023

First Posted (Actual)

October 5, 2023

Study Record Updates

Last Update Posted (Actual)

February 27, 2026

Last Update Submitted That Met QC Criteria

February 23, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 231229

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Individual participant data that underlie the results reported will be made available (including data dictionaries) after de-identification.

IPD Sharing Time Frame

The data will become available 3 months following publication of outcomes and will remain available for at least 5 years.

IPD Sharing Access Criteria

Data will be made available to researchers who provide a methodologically sound proposal that has been approved by the Vanderbilt Institutional Review Board and the study executive committee.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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