Bactericidal Activity of Eugenol-Rich Syzygium aromaticum Essential Oil Against Multidrug-Resistant Bacteria Isolated...

The occurrence of multidrug-resistant (MDR) bacteria in foods of animal origin is a public health concern that underscores the need to investigate natural antimicrobial alternatives. Although Syzygium aromaticum essential oil exhibits antibacterial activity, evidence regarding its bactericidal effects against MDR bacteria recovered from commercial eggs remains limited. This study evaluated the bactericidal activity of eugenol-rich S. aromaticum essential oil (SAEO) and explored its potential antibacterial mechanisms. SAEO was obtained by steam distillation and chemically characterized by gas chromatography-mass spectrometry (GC-MS). Its antibacterial activity was evaluated by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), bacterial growth kinetics, and changes in membrane permeability. Molecular docking was performed to examine the interactions of eugenol with dihydropteroate synthase (DHPS) and β-ketoacyl-acyl carrier protein synthase III (FabH). Eugenol was the predominant constituent (73.9%), followed by dihydroeugenyl acetate (14.1%) and β-caryophyllene (6.0%). SAEO exhibited bactericidal activity against all tested strains, with MIC and MBC values ranging from 0.125 to 0.25 mg/mL and from 0.25 to 0.50 mg/mL, respectively. SAEO also produced sustained bacterial growth inhibition and concentration-associated changes in membrane permeability. Molecular docking predicted favorable interactions of eugenol with DHPS and FabH; however, these interactions require experimental validation. Overall, the findings demonstrate the in vitro bactericidal activity of eugenol-rich SAEO against MDR bacteria recovered from commercial eggs and support further investigation of its potential application in food-safety interventions.