Antibiofilm activity of Vetiveria zizanioides root extract against methicillin-resistant Staphylococcus aureus

Area of Science:

• Microbiology
• Ethnobotany
• Natural Product Chemistry

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant global health threat due to its antibiotic resistance and ability to form biofilms.
• Biofilm formation enhances MRSA's resistance to antibiotics, complicating treatment strategies.
• Folk medicinal plants are increasingly explored for novel therapeutic agents against multidrug-resistant pathogens.

Purpose of the Study:

• To investigate the antibiofilm efficacy of Vetiveria zizanioides root extract against MRSA and its clinical isolates.
• To elucidate the mechanisms underlying the antibiofilm activity of the extract.

Main Methods:

• Treatment of MRSA strains with varying concentrations of Vetiveria zizanioides root extract (VREX).
• Assessment of biofilm formation using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM).
• Analysis of biofilm-related phenotypes (exopolysaccharide, slime, α-hemolysin) and gene expression (fnbA, fnbB, clfA).
• Gas chromatography-mass spectrometry (GC-MS) for phytochemical analysis.

Main Results:

• VREX demonstrated a concentration-dependent reduction in MRSA biofilm formation without impacting bacterial viability.
• SEM and CLSM confirmed significant disruption of biofilm structure by VREX.
• VREX inhibited biofilm-associated factors like exopolysaccharide, slime, and α-hemolysin production.
• VREX treatment led to the downregulation of key adhesion genes (fnbA, fnbB, clfA) and altered cellular factors, as indicated by FT-IR.
• GC-MS analysis identified sesquiterpenes as major compounds in VREX.

Conclusions:

• Vetiveria zizanioides root extract exhibits potent antibiofilm activity against MRSA.
• The extract's mechanism involves targeting adhesion genes and disrupting biofilm matrix components.
• VREX represents a promising natural product for combating MRSA biofilm infections, supporting its ethnobotanical use.