Alumni

Dr Breanna Dixon

Dr Breanna Dixon completed her PhD at C-PACA and the University of Manchester in March 2026. Her research focused on microbial metabolomics, applying mass spectrometry platforms to understand antibiotic resistance, with particular emphasis on carbapenem resistance in Enterobacterales.

Using gas chromatography–mass spectrometry (GC‑MS), her early work demonstrated that antibiotic resistance is associated with distinct metabolic signatures. Volatile profiling showed that β‑lactam‑resistant and susceptible laboratory Escherichia coli variants could be reliably distinguished even in the absence of antibiotic exposure. Extending this approach to a clinical collection of Klebsiella pneumoniae, she identified a leucine‑derived diagnostic ratio (3‑methyl‑1‑butanol/3‑methylbutanal) capable of predicting meropenem susceptibility within six hours of growth.

Beyond volatile metabolites, untargeted liquid chromatography–mass spectrometry (LC‑MS/MS) analyses revealed widespread metabolic alternations in carbapenemase‑producing Enterobacterales (CPE) isolates, particularly affecting amino acid, nucleotide, and cofactor metabolism. This work led to the identification of a panel of metabolic biomarkers for CPE prediction. Finally, CRISPR-mediated plasmid curing confirmed that resistance plasmids independently drive metabolic reprogramming in bacteria, with the metabolome shown to be both host and plasmid-specific.