Enhanced antibacterial and antibiofilm activity of Artemisia aucheri Boiss. extract-loaded niosomes against clinical MRSA isolates.

Aims

To develop and characterize niosomes encapsulating ethanolic Artemisia aucheri extract (Nio-Artemisia) and evaluate their antibacterial and antibiofilm activities against clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates.

Materials And Methods

Niosomes were prepared by thin-film hydration and optimized based on particle size, polydispersity index (PDI), and encapsulation efficiency (EE). Stability and in vitro release were evaluated. Clinical S. aureus isolates were identified using standard microbiological methods, and antibacterial activity was assessed by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and growth kinetics. Antibiofilm activity and expression of icaA and icaB were evaluated using the crystal violet assay and quantitative real-time PCR, respectively.

Results

The optimized formulation had a particle size of 230.2 ± 9.1 nm, PDI of 0.191 ± 0.020, and EE of 72.39 ± 1.45%. Release followed a biphasic pattern and fitted the Higuchi model. Of 30 clinical S. aureus isolates, 15 were MRSA. Niosomal encapsulation reduced MIC values 4- to 16-fold compared with free extract and significantly inhibited biofilm formation. icaA and icaB expression was significantly downregulated (p < 0.001).

Conclusions

Niosomal encapsulation enhanced the antibacterial and antibiofilm activities of A. aucheri extract against clinical MRSA isolates.