2.6. Antibacterial test and modulation of antibiotic activity
The Minimum Inhibitory Concentration (MIC) of essential oil
ofL. sidoides(EOLS), thymol and antibiotics were determined
in BHI by the microdilution assay using suspensions of 10
5
CFU/ml and a drug concentration range of 1024–1lg/ml
(twofold serial dilutions) (Javadpour et al., 1996). MIC was defined as the lowest concentration at which no growth was observed. For the evaluation of EOLS and thymol as a
modulator of antibiotic resistance, MICs of the antibiotics
were determined in the presence of EOLS or thymol at
subinhibitory concentrations (MIC/8), and the plates were
incubated for 24 h at 37C(Coutinho et al., 2008).