Spectroscopic Analysis for Rapid Identification and Characterization of WHO Priority Pathogen— Acinetobacter baumannii

Acinetobacter baumannii (A. baumannii) has emerged as a major multidrug-resistant pathogen due to its ability to acquire antimicrobial resistance (AMR) and form robust biofilms. Unlike conventional methods, advanced spectroscopic techniques enable rapid detection and phenotyping of A. baumannii through distinct spectral signatures for accurate identification and characterization. Raman spectroscopy, including surface-enhanced Raman spectroscopy (SERS) and Fourier-transform infrared (FTIR) spectroscopy can differentiate resistant phenotypes and precise species identification through biomolecular fingerprints, while fluorescence spectroscopy can detects viability and antimicrobial responses using intrinsic or dye-based signals. Nuclear magnetic resonance (NMR) spectroscopy provides detailed metabolic profiling. Applied spectroscopic approaches such as hyperspectral imaging enables label-free detection and quantitative assessment of A. baumannii biofilms, while electrochemical impedance spectroscopy provides real-time monitoring of biofilm dynamics for rapid antimicrobial susceptibility testing (AST). This review highlights the potential role of spectroscopy in generating detailed biophysical and biochemical fingerprints of A. baumannii, supporting the transition from experimental studies to clinical diagnostics. Integration with machine learning (ML) further enhances high-throughput differentiation of colonizing and pathogenic A. baumannii.