Antistaphylococcal and biofilm inhibitory activities of gallic, caffeic, and chlorogenic acids

Abstract

Staphylococcus aureus is a Gram-positive pathogen which is able to form biofilms, exhibiting a more pronounced resistance to antibiotics and disinfectants. The hurdles posed in eradicating biofilms have driven the search for new compounds able to fight these structures. Phenolic compounds constitute one of the most numerous and ubiquitous group of plant secondary metabolites with many biological activities. The aim of the present work was to study the potential antimicrobial and antibiofilm properties of gallic, caffeic, and chlorogenic acids against S. aureus as well to elucidate its mechanism of action. It was concluded that the phenolic acids studied in this work have antistaphylococcal properties. For instance, gallic acid is able to influence the adhesion properties of S. aureus. The phenolic acids tested were also able to inhibit the production of α-hemolysin by this microorganism, with the exception of chlorogenic acid. Regarding its mechanism of action, caffeic acid interferes with the stability of the cell membrane and with the metabolic activity of the cells of S. aureus.

The Emergence of Polyphenols in the Potentiation of Treatment Modality in Cystic Fibrosis

“…Polyphenolic compounds have shown to have antimicrobial properties and hence may have promising therapeutic effects [56]. Gallic acid, found in tea leaves, oak bark, grape seeds, and various vegetables, has been tested against Staphylococcus aureus strains and has been shown to have a higher antibacterial activity than chlorogenic acid [56]. It can also decrease the adhesion capacity of S. aureus to polystyrene, thereby attenuating its ability to form biofilms.…”

“…Phenolic acids have been shown to have antimicrobial qualities at the range of 100-1000 μg mL -1 [58]. Caffeic acid also plays a role in disrupting membrane function of S. aureus by acting as a nucleophile [58] and increasing membrane permeability, depolarizing cell membranes, and reducing respiratory activity, thereby inhibiting the growth of this Gram-positive bacterium [56]. EGCG, a polyphenolic compound found in green tea, has also shown to significantly reduce the metabolic activity to young and mature biofilms; however, this effect was only seen in biofilms produced by S. maltophilia and is thus strain specific [60].…”

“…Biofilms are resistant to antibiotics and disinfectants [57][58][59], and some may carry resistance genes for penicillin antibiotics [56]. Polyphenolic compounds have shown to have antimicrobial properties and hence may have promising therapeutic effects [56]. Gallic acid, found in tea leaves, oak bark, grape seeds, and various vegetables, has been tested against Staphylococcus aureus strains and has been shown to have a higher antibacterial activity than chlorogenic acid [56].…”

“…A biofilm is produced when microorganisms become attached to biotic surfaces and multiply in the extracellular matrix of polymeric substances comprised of proteins and polysaccharides [57,58]. Biofilms are resistant to antibiotics and disinfectants [57][58][59], and some may carry resistance genes for penicillin antibiotics [56]. Polyphenolic compounds have shown to have antimicrobial properties and hence may have promising therapeutic effects [56].…”

“…Biofilms are a major cause of concern in CF because the repercussions of their formation contribute to approximately 80% of all infections [56]. A biofilm is produced when microorganisms become attached to biotic surfaces and multiply in the extracellular matrix of polymeric substances comprised of proteins and polysaccharides [57,58].…”