Combined antibacterial activity of essential oils extracted from Lavandula maroccana (Murb.), Thymus pallidus Batt. and Rosmarinus officinalis L. against antibiotic-resistant Gram-negative bacteria

•Combined antibacterial effects of EOs against resistant bacteria were evaluated.•Individual EOs expressed moderate antibacterial activity towards tested bacteria.•T. pallidus and L. maroccana EO combinations are the most effective against tested bacteria.•All EO combinations tested did not display any antagonism interaction.•EO mixtures provide a promising solution to combat drug resistant bacteria.