The effect of fennel essential oil in combination with antibiotics on Staphylococcus aureus strains isolated from carriers

- The effect of fennel essential oil in combination with antibiotics against Staphylococcus aureus strains was presented.
- Fennel oil combined with cefoxitin, mupirocin, co-trimoxazole and ciprofloxacin increased the activity of these antibiotics.
- The highest inhibitory effect of fennel essential oil in combination with mupirocin was showed.

An increase in the number of staphylococcal infections and carriers among medical staff has forced us to seek more and more effective antibacterial agents. Bacteria from the Staphylococcus genus possessing different mechanisms of resistance are the cause of nosocomial infections. The objective of our investigations was susceptibility of S. aureus strains isolated from nasal vestibule of medical students to fennel essential oil. The GC-MS analysis of fennel essential oil revealed eleven constituents among which a majority of trans-anethole (80%) was found. The D-tests showed iMLSB (80%), cMLSB and MSB (10%) resistant phenotypes of S. aureus. The S. aureus isolates were intermediate to mupirocin (45%). Fennel essential oil increased the inhibition zone around cefoxitin, mupirocin, co-trimoxazole and ciprofloxacin with statistical significance. Our research showed that the fennel essential oil in combination with mupirocin may be considered as a natural alternative in eradication of S. aureus with iMLSB, cMLSB, MSB resistant phenotypes and is able to decrease the growth rate of antibiotic resistance.