Microbial profiling through volatile organic compounds as a route toward rapid detection of bacterial infections

Bacterial infections remain a critical global health challenge, particularly in clinical settings where antimicrobial resistance is rising. Rapid diagnostic tools are crucial for enabling timely therapeutic interventions and mitigating disease burden. Bacterial species produce distinct profiles of volatile organic compounds (VOCs) that serve as biochemical fingerprints, making VOC detection a promising noninvasive approach for rapid pathogen identification in clinical and environmental samples.This review provides a comprehensive overview of VOC profiles associated with ESKAPE-E pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species, and Escherichia coli), integrating findings from controlled laboratory studies and clinically relevant patient-derived samples. Several VOCs consistently correlate with specific species, including isovaleric acid with S. aureus, indole with E. coli, and hydrogen cyanide with P. aeruginosa. Conversely, compounds such as dimethyl sulfide, dimethyl disulfide, ethanol, 2-phenylethanol, and 2-undecanone occur across multiple species, supporting pattern-based rather than single-marker diagnostic strategies.By synthesizing current evidence, we identify key knowledge gaps, including the limited characterization of certain pathogens and the need to advance VOC research toward clinically relevant, disease-oriented applications. We also discuss emerging analytical and sensing technologies that could enhance VOC detection and facilitate the integration of VOC-based diagnostics into routine clinical practice.