Our findings demonstrated that the addition of the T. saturejoides EOs enhanced the anti-bacterial effect of cefixime. A similar interaction between other Thymus EOs in combination with antibiotics against pathogenic microorganims has been previously reported ( Fadli et al., 2012 and Saad et al., 2010). The interesting capacity observed in T. satureoides EOs obtained from Er-rich population to cause significant decrease in the MIC values of cefixime might be explained by the presence of high content of carvacrol (45.3%), as previously reported in others Thymus species ( Fadli et al., 2012). In fact, it has been suggested that this phenolic compound and its isomer thymol, the major compounds of thyme EOs, may act as membrane permeabilizers, enhancing the intake of antibiotics