Mechanistic Insights Into the Effect of the Essential Oil of Ambrosia hispida Pursh. Against Multidrug‐Resistant Clinical Isolates of Acinetobacter baumannii

The emergence of antimicrobial‐resistant bacteria has significantly compromised global public health. The World Health Organization has identified priority pathogens for research and new therapeutic strategies, highlighting carbapenem‐resistant Acinetobacter baumannii as a critical priority. Ambrosia hispida essential oil (EO) from the Yucatan Peninsula was investigated for its anti‐ A. baumannii properties. GC–MS analysis identified 27 metabolites, predominantly sesquiterpenes and oxygenated sesquiterpenes, with spathulenol, caryophyllene oxide, and α‐pinene as major compounds. This EO exhibited antibacterial activity against A. baumannii strains, strong inhibition of biofilm formation, and anti‐quorum‐sensing activity. Moreover, the EO also decreased bacterial survival in response to H 2 O 2 , indicating anti‐catalase activity. Scanning electron microscopy (SEM) analysis confirmed the EO's ability to inhibit biofilm formation and cause morphological alterations in bacterial cells. Molecular docking studies revealed that kaurene, a diterpene in the EO, had the strongest interaction with bacterial targets involved in biofilm formation. The study highlights the potential of A. hispida EO as a promising candidate for developing agents to combat carbapenem‐resistant A . baumannii .