Antimicrobial and anti-biofilm activity of manuka essential oil against and of food origin.

The activity of manuka () essential oil (EO) on biofilms of foodborne and has been studied. Seven strains of and 7 of (5 methicillin-resistant) were tested. EO minimal inhibitory concentration (MIC), EO minimal bactericidal concentration (MBC) and biofilm production quantification were determined for each strain by microtiter methods. Moreover, EO Minimum Biofilm Inhibitory Concentration (MBIC) and Minimum Biofilm Eradicating Concentration (MBEC) were determined on 2 and 3 that showed the best biofilm production. Finally, on 4 strains out of 5 (2 and 2 ) EO Biofilm Reduction Percentage (BRP) . untreated controls was assessed after a treatment with EO subinhibitory concentrations. The chemical composition of manuka essential oil was determined by Gas Chromatography- Electron Impact Mass Spectrometry (GCEIMS). The manuka EO demonstrated good antimicrobial activity: MIC and MBC were 0.466 mg/ml and 0.933 mg/ml, respectively, whereas MIC and MBC were 0.233 mg/ml and 0.466 mg/ml, respectively. Furthermore, showed a MBIC of 0.933 mg/ml and a MBEC in the range of 0.933-1.865 mg/ml, whereas had a MBIC in the range of 7.461-14.922 mg/ml and a MBEC of 14.922 mg/ml. revealed no significant BRP after the treatment with manuka EO, whereas showed a BRP higher than 50% with MIC/2 and MIC/4 EO concentrations. These results provide information for feasible manuka EO applications in food production systems.