Antimicrobial Activity of the Green Tea Polyphenol (−)-Epigallocatechin-3-Gallate (EGCG) against Clinical Isolates of Multidrug-Resistant Vibrio cholerae

Abstract

The spread of multidrug-resistant (MDR) Vibrio cholerae necessitates the development of novel prevention and treatment strategies. This study aims to evaluate the in vitro antibacterial activity of green tea polyphenol (−)-epigallocatechin-3-gallate (EGCG) against MDR V. cholerae. First, MIC and MBC values were evaluated by broth microdilution techniques against 45 V. cholerae strains. The checkerboard assay was then used to determine the synergistic effect of EGCG and tetracycline. The pharmaceutical mode of action of EGCG was clarified by time-killing kinetics and membrane disruption assay. Our results revealed that all of the 45 clinical isolates were susceptible to EGCG, with MIC and MBC values in the range of 62.5–250 µg/mL and 125–500 µg/mL, respectively. Furthermore, the combination of EGCG and tetracycline was greater than either treatment alone, with a fractional inhibitory concentration index (FICI) of 0.009 and 0.018 in the O1 and O139 representative serotypes, respectively. Time-killing kinetics analysis suggested that EGCG had bactericidal activity for MDR V. cholerae after exposure to at least 62.5 µg/mL EGCG within 1 h. The mode of action of EGCG might be associated with membrane disrupting permeability, as confirmed by scanning electron microscopy. This is the first indication that EGCG is a viable anti-MDR V. cholerae treatment.

Enantioselective Synthesis of Flavonoids and Their Diverse Applications in Nutrition, Health, and Medicine: A Mini Review

“…Scanning electron microscopy (SEM) suggests that the physiological mechanism of action of EGCG may be related to membranes disrupting permeability. This is the first proof that EGCG works as a practical anti‐MDR V. cholerae medication [123] …”

Improving fresh strawberry shelf life and quality by using the fresh‐keeping paper embedded with oregano essential oil and tea polyphenols

“…Furthermore, OEO has been found to inhibit the tricarboxylic acid cycle pathway and its key enzymes, leading to effects on metabolites (Cui et al ., 2019). Studies have reported that the bactericidal effects of TP are mainly achieved through physical and chemical interactions of their chemical components with microbial cells (Sun et al ., 2021; Siriphap et al ., 2022). The main chemical components contained in TP are tannins, flavonoids and aromatic compounds, which can disrupt microbial cell membranes and cell walls, leading to the leakage of microbial cell contents and ultimately cell death (Yang & Zhang, 2019).…”

Antioxidant, Antibacterial and Antiqourum Sensing Properties of Selected Wild Tea Leaves of Mountain Province

“…The green tea catechins also manifest widerange of antibacterial activity through different mechanisms. 31 Specifically, this antibacterial property is due to the presence of phenolic compounds and flavonoids which are hydroxylated phenolic substances known to be produced by plants as a protective mechanism against microbial infection, and they have been determined to have antimicrobial substances against a broad array of microorganisms in vitro. 32 In this present study, all of the wild tea plants have the potential antiquorum sensing property through the prevention of the formation of biofilm of the different bacterial species.…”