Investigation of the antimicrobial and antibiofilm effect of plant Consolida orientalis on methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococcus sp. (VRE)

This study was planned to investigate the antimicrobial and antibiofilm effects of Consolida orientalis on MRSA and VRE. MRSA and VRE strains isolated from patients admitted to Sivas Cumhuriyet University Medical Faculty Practice and Research Hospital were used in the study. The antimicrobial activity of C. orientalis was investigated by microdilution broth method, biofilm formation activity of microorganisms by spectrophotometric plate method and antibiofilm activity of plant extract by microtiter plate method. According to the results, MRSA strains had Minimum Inhibitory Concentration (MIC) values between 0.15 and >5 mg/mL while VRE strains had MIC values between 0.625 and 2.5 mg/mL. Twenty MRSA strains were observed to form biofilm at various levels, 8 of which were strong, 10 were moderate and 2 were weak. Sixteen strains formed biofilms, 1 of which was strong, 15 of which was weak, and 4 strains did not form biofilms. In conclusion, C. orientalis plant extract showed moderate to weak antimicrobial activity against MRSA and VRE pathogens. The presence of the substance 2-ethylacridine, which is hypothesised to possess anti-biofilm properties, was identified in the plant extract through the utilisation of gas chromatography/mass spectrometry (GC/MS) analysis. The extract was also found to inhibit biofilm and eradicate bacteria at various levels.