Phytochemical profiling as a solution to palliate disinfectant limitations

Area of Science:

• Microbiology
• Natural Product Chemistry
• Antimicrobial Resistance

Background:

• Indiscriminate biocide use drives antimicrobial tolerance in microorganisms.
• Need for alternative antimicrobial agents to combat resistant strains.

Purpose of the Study:

• To evaluate seven phytochemicals for controlling planktonic and sessile Staphylococcus aureus and Escherichia coli.
• To identify potent phytochemicals as alternatives or complements to conventional biocides.

Main Methods:

• Screening of seven phytochemicals: tyrosol, caffeic acid, ferulic acid, cinnamaldehyde, coumaric acid, cinnamic acid, and eugenol.
• Determination of Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentrations (MBC).
• Assessment of efficacy against planktonic and sessile bacterial cells, including membrane hydrophilicity changes.

Main Results:

• Cinnamaldehyde and eugenol exhibited antimicrobial activity against S. aureus and E. coli.
• Cinnamic acid demonstrated complete control of adhered bacteria, comparable to peracetic acid and sodium hypochlorite.
• Cinnamic acid significantly altered bacterial membrane hydrophilicity, suggesting a mechanism of action.

Conclusions:

• Phytochemicals represent viable alternatives or complementary agents to conventional biocides.
• Cinnamic acid is particularly effective against sessile bacterial cells, addressing biofilm challenges.
• Further research into phytochemicals can mitigate the rise of antimicrobial tolerance.