# The Use of MALDI TOF for the Rapid Detection of Carbapenemases from Clinical Isolates

> **NIH NIH K23** · JOHNS HOPKINS UNIVERSITY · 2020 · $183,430

## Abstract

Project Summary
I am an Assistant Professor of Pediatrics at The Johns Hopkins University School of Medicine and am very
committed to improving my understanding of the mechanisms of Gram-negative resistance so I can ultimately
become a future leader in developing, validating, and implementing rapid diagnostics for the detection of
multidrug-resistant Gram-negative organisms (MDRGNs).
In 2013, the Centers for Disease Control and Prevention assigned the highest threat level to carbapenemase-
producing Enterobacteriaceae (CPE), declaring they require urgent public health attention. CPE are endemic
in the US mid-Atlantic region, representing 13% of clinical isolates of healthcare-acquired Klebsiella
pneumoniae. CPE bacteremia are associated with mortality upwards of 60%. Improving outcomes of patients
with CPE bacteremia requires their prompt detection to ensure patients receive optimal antibiotic therapy as
early as possible. There is no standardized, easy-to-use, reliable assay for carbapenemase detection. Most
diagnostic laboratories do not test for carbapenemase production, potentially leading to poor patient outcomes.
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) is a technology used
to detect microorganisms that has become increasingly commonplace in diagnostic laboratories. It is rapid,
cost-effective, and accurate. Species and genus identification are available in as little as 10 minutes from the
time bacterial growth is detected in sterile specimens. MALDI TOF is currently not being used for the
identification of antibiotic resistance in clinical practice. We believe we can capitalize on this FDA-approved
technology to detect carbapenemases directly from blood culture broths at least 27 hours earlier than existing
methods. Although the distribution of carbapenemases endemic to the mid-Atlantic US has not been previously
characterized, it is estimated that approximately 50% of carbapenemases are KPC-3 carbapenemases. Our
preliminary data indicate that MALDI TOF can be successfully used to identify the presence of KPC-3
carbapenemases. We believe that we can expand upon this and build a comprehensive MALDI TOF library to
rapidly detect the wide variety of carbapenemases endemic to the US. The overarching goals of this proposal
are to (a) identify the organism and carbapenemase-encoding gene combinations in a highly endemic region
for CPE using existing isolates from 8 hospitals; (b) develop a comprehensive MALDI TOF library for the rapid
detection of carbapenemases directly from positive bloodstream isolates with the goal that this library can
eventually be exported to clinical microbiology laboratories across the country for rapid detection of CPE; and
(c) determine the accuracy and potential impact of MALDI TOF on optimizing antibiotic therapy for patients
admitted to any of 5 hospitals in the Hopkins Health System with CPE bacteremia. Because the K23
mechanism does not allow for experimental diagno...

## Key facts

- **NIH application ID:** 9822166
- **Project number:** 5K23AI127935-04
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Pranita Tamma
- **Activity code:** K23 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $183,430
- **Award type:** 5
- **Project period:** 2016-12-09 → 2020-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9822166

## Citation

> US National Institutes of Health, RePORTER application 9822166, The Use of MALDI TOF for the Rapid Detection of Carbapenemases from Clinical Isolates (5K23AI127935-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9822166. Licensed CC0.

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