The global rise of multidrug-resistant (MDR) Gram-negative bacteria such as Escherichia coli, Klebsiella pneumoniae, and Salmonella typhi poses a major public health challenge. Conventional antibiotics are losing efficacy due to resistance mechanisms, including efflux pumps, enzymatic degradation, and biofilm formation. This study investigates the antimicrobial activity of ethanol extracts of Murraya koenigii (Curry Leaf), a medicinal plant belonging to the Rutaceae family. The leaves are rich in carbazole alkaloids like mahanimbine, girinimbine, and koenimbine, which have demonstrated antibacterial and antioxidant potential. Ethanolic extracts were tested using the agar well diffusion method against Gram-negative strains. Results revealed moderate inhibitory effects, with inhibition zones of 13.6 mm for E. coli, 12.9 mm for K. pneumoniae, and 12.4 mm for S. typhi, compared to 22–24 mm for ciprofloxacin. Although less potent than standard antibiotics, M. koenigii offers promising natural antimicrobial properties with reduced chances of resistance. This research validates traditional medicinal use and highlights its potential in developing plant-based antimicrobial formulations.
Yadav et al. (Tue,) studied this question.