Additive antibacterial activity of naringenin and antibiotic combinations against multidrug resistant Staphylococcus aureus

Abstract

Methicillin-resistant Staphylococcus aureus has been causing numerous problems in the health care sector. This is mainly due to its ability to develop resistance to a number of antibiotics used to treat staphylococcal infections. Medicinal plants have been used to treat various ailments over the years and are generating a lot of interest as alternative treatment options. Naringenin is a plant derived flavonoid that possesses antibacterial properties, among others. This study assessed the effect of combinations of naringenin and four antibiotics against two Staphylococcus aureus strains. The minimum inhibitory concentrations were determined using the disk diffusion and broth microdilution assays. In the disk diffusion assay, naringenin did not inhibit bacterial growth, nor did it enhance the antibacterial activity of the antibiotics in the combination study. This was attributed to its slow rate of diffusion out of the disks. On the contrary, in the broth microdilution assay, naringenin exhibited additive effects when combined with the antibiotics (at sub-inhibitory concentrations). These results show the potential of naringenin as an antibacterial agent. Furthermore, the additive effects observed at low naringenin concentrations showed that it can potentially be used in combination with antibiotics against multidrug resistant bacteria.