Antibacterial and antibiofilm effect of essential oils on staphylococci isolated from cheese - application of the oil mixture in a cheese model

The aim of the research was to examine the antimicrobial and antibiofilm effects of angelica, immortelle, laurel, hyssop, and sage plant dust essential oils (EOs) against isolated strains of Staphylococcus spp. from cheeses, in vitro and in the model of white cheese. MALDI-TOF MS analysis confirmed two Staphylococcus aureus strains and two coagulase-negative, identified as S. saprophyticus and S. warneri. All isolates produce biofilm, where the strains of S. aureus showed slightly better adherence. The main component of angelica EO was β-phellandrene (48.19 %), while α-pinene (20.33 %) were dominant in immortelle EO, in hyssop EO cis-pinocamphone (37.25 %), in laurel EO 1,8-cineole (43.15 %) and in sage EO epirosmanol (26.25 %). The sage EO exhibited the strongest antistaphylococcal activity against all isolates. Synergism was also detected in combination of sage with hyssop or laurel EO. Better antibiofilm activity was confirmed for sage EO compared to hyssop EO. The mixture of sage/laurel EOs reduced the total number of staphylococci in the cheese after 4 days. Results indicate that in vitro applied EOs showed significant antistaphylococcal and antibiofilm activity, while the oil mixture reduced the initial total number of staphylococci.