Synergistic interactions of essential oil components with antibiotics against multidrug-resistant Corynebacterium striatum.

This study focuses on evaluating the antibacterial activity of essential oil components (EOCs)—specifically carvacrol (CAR), cinnamaldehyde (CIN), thymol (TH), alpha pinene (α-PN), eucalyptol (EU), and limonene (LIM)—and several antibiotics against 50 multidrug-resistant Corynebacterium striatum strains isolated from clinical specimens. Using broth microdilution and checkerboard methods, the research found that all strains were susceptible to vancomycin (VAN) and linezolid (LZD) but resistant to gentamicin (GEN), penicillin (PEN), ciprofloxacin (CIP), and clindamycin (CLN). Notably, synergistic interactions were observed between CAR and CIN combined with antibiotics VAN, LZD, GEN, CIP, and CLN, suggesting that these EOCs can enhance antibiotic efficacy and potentially reduce resistance in C. striatum. This investigation represents the first report of such synergistic activity involving essential oil components and antibiotics against C. striatum, highlighting a promising approach to combat multidrug resistance in this emerging nosocomial pathogen.