Objective: To evaluate in vitro antibacterial effectiveness of five medicinal plants used by an Indian aborigine, against 8 multidrug-resistant (MDR) enteropathogenic bacteria isolated from clinical samples of under-5 hospitalized children.
Methods: Antibiotic sensitivity patterns of eight clinically isolated strains of enteropathogenic bacteria, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Salmonella paratyphi, S. typhi, Shigella dysenteriae, S. sonnei and Vibrio cholerae were assessed by disc-diffusion method. Antibacterial activities of 8 solvent-extracts of leaves and bark of five medicinal plants were monitored by the agar-well diffusion method. The microbroth dilution method was used to assess minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Qualitative phytochemical analyses of active plant extracts were carried out.
Results: Ethanol, ethyl acetate and methanol extracts of Holarrhena antidysenterica leaf tissue were most effective against 8 MDR pathogens in vitro. Similarly, acetone, ethanol and methanol extracts of Terminalia alata leaf tissue; chloroform, ethyl acetate and methanol extracts of Terminalia arjuna leaf tissue and ethyl acetate, ethanol and methanol extracts of Paederia foetida leaf tissue were most effective in inhibiting in vitro growth of the 8 MDR enteropathogens. Ethyl acetate and methanol extracts of H. antidysenterica bark tissue; acetone, ethanol and methanol extracts of T. alata bark tissue and acetone, ethanol and methanol extracts of T. arjuna bark tissue were most effective in controlling enteropathogen growth. The minimum inhibitory concentration and minimum bactericidal concentration values of the 3 most antimicrobial leaf and bark extracts from the five plants were in the range of 1.56 to 50 mg/mL.
Conclusion: These 5 plants exhibited in vitro control over a cohort of 8 enteropathogenic bacterial strains isolated from clinical samples.