Combating Biofilm by Targeting Its Formation and Dispersal Using Gallic Acid against Single and Multispecies Bacteria Causing Dental Plaque

Abstract

Exploring biological agents to control biofilm is a vital alternative in combating pathogenic bacteria that cause dental plaque. This study was focused on antimicrobial, biofilm formation and biofilm dispersal efficacy of Gallic acid (GA) against bacteria, including Proteus spp., Escherichia coli, Pseudomonas spp., Salmonella spp., Streptococcus mutans, and Staphylococcus aureus and multispecies bacteria. Biofilm was qualitatively and quantitatively assessed by crystal violet assay, florescence microscopy (bacterial biomass (µm2), surface coverage (%)) and extracellular polymeric substances (EPS). It was exhibited that GA (1–200 mg/L) can reduce bacterial growth. However, higher concentrations (100–200 mg/L) markedly reduced (86%) bacterial growth and biofilm formation (85.5%), while GA did not exhibit any substantial dispersal effects on pre-formed biofilm. Further, GA (20–200 mg/L) exhibited 93.43% biomass reduction and 88.6% (p < 0.05) EPS (polysaccharide) reduction. Microscopic images were processed with BioImageL software. It was revealed that biomass surface coverage was reduced to 2% at 200 mg/L of GA and that 13,612 (µm2) biomass was present for control, while it was reduced to 894 (µm2) at 200 mg/L of GA. Thus, this data suggest that GA have antimicrobial and biofilm control potential against single and multispecies bacteria causing dental plaque.

Characterization, antibacterial, antioxidant, antidiabetic, and anti-inflammatory activities of green synthesized silver nanoparticles using Phragmanthera austroarabica A. G. Mill and J. A. Nyberg extract

“…Minimum inhibitory concentrations (μg/ml) of P. austroarabica extract and AgNPs obtained using agar plate diffusion assay are shown in Table 6 . Our results coincide with previous reports ( Xu and Lee, 2001 ; Cushnie and Lamb, 2005 ; Li et al, 2015 ; Jaisinghani, 2017 ; Abhishek et al, 2019 ; Marrez et al, 2019 ; Yang et al, 2020 ; Albutti et al, 2021 ; Nguyen and Bhattacharya, 2022 ; Qanash et al, 2022 ) that demonstrated the strong antimicrobial activity of either phenolics (namely gallic acid), flavonoids (in particular quercetin) or plant extract rich in these chemical constituents toward a number of microorganisms including P. vulgaris , P. aeruginosa , K. pneumoniae , and MRSA. These pathogens are well-documented eitological agents that were previously reported to be associated with hospital acquired infections ( Khan et al, 2015 ; Haque et al, 2018 ; Centers for Disease Control and Prevention (CDC), 2019 ).…”

“…Additional antibacterial activity has been reported for quercetin through targetting DNA gyrase and interfering with nucleic acid synthesis ( Simoes et al, 2009 ; Osonga et al, 2019 ). Moreover, antibiofilm activity aginst oral pathogens forming dental plaques have also been demonstrated ( Albutti et al, 2021 ). Furthermore, anti-proteus activity of natural plant extracts rich in gallic acid and quercetin have also been reported for Proteus mirabilis , a principle cause for urinary tract infections and kidney stone formations.…”

“…The biosynthesis of AgNPs of the total extract of P. austroarabica was done using a modified method, as previously reported by Mortazavi-Derazkola et al (2021), with slight modifications. Initially, 10 mg of the extract were dissolved in 1 ml ethanol, then added to 10 ml of 10 mM AgNO 3 .…”

Alkyl Gallates as Potential Antibiofilm Agents: A Review

“…Gallic acid (GA), found in many plant extracts, is a natural phenolic compound with potent antioxidant and antimicrobial actions against various pathogenic bacteria [ 19 , 20 , 21 , 22 ]. Many studies have documented its antimicrobial effect on biofilm formation and its ability to combat pathogenic bacteria [ 19 , 20 , 21 , 22 ]. Biofilm formation in bacteria is closely associated with the threat of infection and is a major mechanism of resistance against antimicrobial agents.…”

Recent advances on the regulation of bacterial biofilm formation by herbal medicines

“…Gallic acid at a concentration of 2 mg/ml significantly inhibits the expression of pgaABCD genes and effectively suppress the formation of E. coli biofilm in a dose-dependent manner ( Kang et al, 2018 ). Moreover, high concentrations of gallic acid inhibited the biofilm formation and growth of Proteus spp., Pseudomonas spp., Salmonella spp., Streptococcus mutans , and S. aureus ( Albutti et al, 2021 ). In vivo , gallic acid reduces inflammation and proliferation of Brucella abortus in spleens of mice ( Reyes et al, 2018 ).…”