Essential Oils as Antimicrobial Agents Against WHO Priority Bacterial Pathogens: A Strategic Review of In Vitro Clinical Efficacy, Innovations and Research Gaps

The text highlights that antimicrobial resistance is escalating globally while antibiotic development lags, prompting interest in alternative antimicrobial strategies. Plant-derived essential oils (EOs) have gained attention because they exhibit broad antibacterial activity, act through multiple mechanisms, and can potentiate existing antibiotics. Over the past decade, studies have shown that EOs can disrupt biofilms, inhibit quorum sensing, modulate efflux pumps, and even reverse resistance in clinically isolated multidrug-resistant and extensively drug-resistant pathogens, including WHO-listed priority bacteria. Technological advances in analytics, omics, and microfluidics have deepened understanding of EO mechanisms and may support future therapeutic development. However, challenges—including inconsistent composition, lack of standardized assays, and limited in vivo evidence—still constrain clinical application. This scoping review therefore aims to synthesize recent progress on the antibacterial activity of plant EOs against clinical isolates and assess their potential contribution to combating AMR.