Synergistic Effects of Selected Herbal Plant Extracts with Antibiotics Against Carbapenem-Resistant Escherichia Coli: A Systematic Review

Background: The rapid emergence of carbapenem-resistant Escherichia coli (CREC) infections is a major threat to global public health, prompting the search for alternative therapeutic options. In this review, the latest research on the antimicrobial activity and synergy of herbal plant extracts on carbapenem-resistant Escherichia coli (CREC) and multidrug-resistant (MDR) clinical isolates is discussed. Key findings point to the capacity of equol, naringenin, and tetrandrine to reinstate the effectiveness of conventional antibiotics, including carbapenems and colistin. Furthermore, the mechanisms of action include the disruption of cell wall and membrane integrity, the inhibition of efflux pump activity, and the downregulation of resistance genes, including carbapenemases and mcr-1. Synergistic interactions, indicated by a Fractional Inhibitory Concentration (FIC) index of less than 0.5, reveal the potential of plant-derived compounds as effective adjuvants. Although in vivo studies in murine models indicate a positive outcome in terms of reduced bacterial loads, translation to the clinic is hindered by a lack of human studies and standardized extraction methodologies. This report presents a holistic overview of these plant-derived approaches, revealing a glimpse of their potential as next-generation antimicrobials.