Extraordinary science with Iulia Macavei

The Biomolecular Mass Spectrometry team from Jérôme Lemoine at the Institut des Sciences Analytiques investigates the impactful role of proteomics in sepsis management

  • “Having a fast and accurate method for identifying pathogen species and their antibiotic resistance profile is crucial for successful sepsis management”

    Iulia Macavei Institute of Analytical Sciences

Investigating the impactful role of proteomics in sepsis management

Approximately 1.3 million people die each year worldwide from bacterial antimicrobial resistance (AMR), particularly in the context of bloodstream infections (BSIs) that develop into sepsis. Although matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) has significantly reduced the time it takes to identify pathogens, the evaluation of AMR is still based on growth tests in the presence of antibiotics. This negatively impacts the diagnosis turnaround time, which delays the administration of effective antimicrobial agents to the patient.

To streamline the turnaround time to less than an hour from a positive blood culture, researchers evaluated the sensitivity and specificity of SWATH data-independent acquisition (DIA) to simultaneously provide the identity and antibiotic resistance profile of pathogens associated with BSIs based on peptide surrogates.

Key takeaways

  • The role of proteomics in sepsis management
  • How the sensitivity and specificity of MS with DIA can be used to identify a pathogen and determine its antibiotic susceptibility profile
  • The potential for ultra-fast microorganism identification in blood cultures

Watch Iulia Macavei’s extraordinary science

Fast and accurate identification and antibiotic resistance profiling of microorganisms in blood cultures by SWATH DIA proteomics

About the presenter

Iulia Macavei
Institute of Analytical Sciences

Iulia Macavei works with Professor Jérôme Lemoine at the Institute of Analytical Sciences in Villeurbanne, France. She focuses on developing innovative approaches to rapidly diagnose sepsis directly from a positive blood culture. Iulia has a background in biochemistry and received her BSc from the University of Grenoble Alpes. She then pursued her passion for mass spectrometry-based approaches in bioanalysis and received her MSc in analytical chemistry from the University of Lyon.

The fundamentals behind extraordinary science

Zeno trap
The innovation of the Zeno trap solves the duty cycle issue observed on other QTOF instruments. As ions are accumulated in the Zeno trap before being pulsed rapidly into the TOF, up to 20x more fragment ions can be detected. Each TOF experiment therefore acquires more useful MS/MS information, including for lower abundance species that were previously undetectable. The use of the Zeno trap introduces researchers to a new level of sensitivity.
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Zeno SWATH data-independent acquisition (DIA) combines the sensitivity of the Zeno trap with the reproducibility and precision of SWATH DIA to deliver unprecedented levels of analyte identification and quantitation. The 6–10x sensitivity gains in MS/MS mode that the Zeno trap provides through duty cycle improvements deliver up to 3x more identified proteins and approximately 3–6x more quantified proteins at loads less than 20 ng. This leads to a more comprehensive understanding of underlying biological changes. With Zeno SWATH DIA, maximal information is obtained from each precious sample.
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Electron associated dissociation (EAD)
EAD is a step-change in fragmentation technology that allows for a range of free electron-based fragmentation mechanisms within 1 device. The ability to tune electron kinetic energy within an EAD experiment extends the utility of the approach to all molecule types, ranging from singly charged small molecules to large multiply charged proteins.
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