Using LC-IM-MS/MS for Bacterial Strain Discrimination

On Thursday, September 11, from 12:00–12:30 PM in the Conference Room, Ahmed Hamid, Assistant Professor in the Department of Chemistry and Biochemistry at Auburn University, delivered a talk titled “Strain-Level Differentiation of Microorganisms using High-Resolution Ion Mobility Mass Spectrometry.”

Antimicrobial resistance was presented as a growing global health threat, with forecasts estimating up to 10 million deaths annually by 2050 if effective countermeasures are not developed (1). Central to addressing this crisis was the ability to rapidly and accurately identify microorganisms responsible for infection. Hamid explained how his research focused on bacterial membrane lipids as diagnostic biomarkers, since these molecules often vary by species and strain (1). However, he noted that structural complexity, such as differences in acyl chain position and double bond geometry, makes full lipid characterization highly challenging (1).

The presentation highlighted how combining ambient ionization techniques and liquid chromatography with high-resolution ion mobility and tandem mass spectrometry (LC–IM-MS/MS) provided a powerful pathway toward precise microbial characterization. The method enhanced structural resolution and enabled discrimination of microorganisms at both the species and strain levels with strong predictive accuracy (1).

A key element of the work involved applying machine learning to LC–IM-MS/MS data sets (1). In a demonstration using artificially contaminated urine samples, this approach successfully differentiated eleven strains of E. coli by analyzing isomeric lipid, metabolite, and peptide biomarkers. The integration of advanced data analytics with multidimensional separation technologies was shown to hold strong promise for clinical diagnostics (1).

By showing how molecular-level information could be rapidly translated into actionable identification, Hamid’s presentation pointed to a future where faster, more accurate microbial detection may help curb antibiotic misuse and improve patient outcomes (1).

LCGC International spoke to Hamid about his talk and research. In this clip, Hamid addresses the advantages of using LC-IM-MS/MS over traditional microbial lipid profiling techniques and how ion mobility overcomes several key challenges in this space.

This interview segment is part of our conversation with Hamid. Throughout the next week, we will be publishing our coverage of the Analytica USA conference. To stay up to date with all the latest from our coverage of Analytica USA, click here.

Reference

1. Analytica USA, Strain-Level Differentiation of Microorganisms using High-Resolution Ion Mobility Mass Spectrometry. Analytica USA. Available at: https://aus2025.mapyourshow.com/8_0/sessions/session-details.cfm?scheduleid=29 (accessed 2025-09-10).