Evaluation of the Antimicrobial Activity of Plant-Derived Extracts Against Multidrug-Resistant Bacteria

Abstract

The worldwide expansion of antimicrobial resistance (AMR) is a major challenge to human health management, especially in the case of infected wounds. This review is a comprehensive evaluation of the latest research works on the effectiveness of plant-based extracts as potential antimicrobial agents against multidrug-resistant (MDR) bacterial pathogens. We review 49 publications from 2009 to 2019 that researched on antibacterial activity of the plant extracts such as Moringa oleifera, Matricaria chamomilla, Cinnamomum verum and others against MDR strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The antimicrobial activity assessment methods, mostly disk diffusion and broth dilution, are covered. The results show that in many instances various crude extracts and phytochemical constituents have demonstrated a great potential of inhibitory effect against antibiotic-susceptible as well as resistant strains and mostly through cell wall or membrane damage and use of mechanisms other than the conventional ones. We provide tables that summarize the major research, plant sources, target bacteria, and results. This paper argues that plant-based extracts constitute a sustainable and green source of novel antimicrobial compounds and agents for MDR infection that can be used in combination with antibiotics, thus worthy of further research in terms of their isolation, standardization, and mechanisms of action.