The antibacterial properties of methanolic extract of Teucrium polium against MRSA

Background: Infections due to resistant Staphylococcus aureus strains are progressively increased annually. So, finding new antibiotic resources is of great importance. Medicinal plants as a natural source of antibiotics are considered a good option. Teucrium polium, a native plant in Khouzestan, has been used for a long time in folk medicine. The aim of the present study was to investigate the antibacterial potential of this plant against methicillin resistant S. aureus (MRSA) strains.

Methods: Methanolic extract was prepared from the flowers of T. polium, and its antibacterial activity was evaluated against 50 MRSA isolates by Kirby-Bauer disc diffusion method. These isolates were also screened for mec and pvl genes.

Results: From 50 isolates, 20 isolates were selected and subjected to antibacterial analysis. From these, 14 isolates were positive for mecA gene, 2 of them were positive for pvl gene and 4 of them didn't have mec or pvl genes. None of MRSA isolates were positive for both genes. The results showed that the methanolic extract of T. polium has considerable inhibitory effect against MRSA, even at the lowest concentration. mecA and pvl negative strains were more sensitive to methanolic extract, but the presence of mecA didn not have any significant effect on their resistance.

Conclusion: Based on these findings and with regard to the increasing trend in hospital-acquired S. aureus infections, it can be suggested that T.polium is an effective medicinal plant for treatment of infections caused by this bacterium and can be used as a natural source to produce new antibiotics.