Process Optimization of Antimicrobial Activity of Adhatoda vasica Against MDR Pathogens Using Response Surface Methodology

Multidrug resistance (MDR) pathogens Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumoniae , Acinetobacter baumannii , Pseudomonas aeruginosa , and Enterobacter species are the main causative agents of infections in a majority of both developed and underdeveloped countries hospitals. Medicinal plant-based antimicrobial agents can be used as an alternate source to treat microbial infection caused by antibiotic-resistant microorganisms. The present study was designed to evaluate antimicrobial properties of Adhatoda vasica plant leave methanolic extract against three MDR pathogens isolated from local hospital and identified using 16S rRNA, viz. S. aureus , P. aeruginosa, and A. pitti . In the present study, Soxhlet extraction methodology was used to optimize the bioactive compounds from A. vasica leaves. The ideal extraction parameters for the highest antibacterial activity in terms of zone of inhibition were duration (30 min), temperature (70 °C), and solid–liquid ratio (30 g/L) utilizing response surface methodology and central composite design (mm). Analysis of antimicrobial activity was performed against three MDR pathogens, namely S. aureus , P. aeruginosa , and A. pitti , by using disk diffusion assay. GC–MS profiling revealed the presence of active phytochemicals such as 6,9,12-octadecatrienoic acid, phenylmethyl ester, and phytol known for pharmacological importance. From the present work, it can be concluded that A. vasica extracts could be a viable source to combat infection caused by MDR pathogens in both community and hospital settings.