Antibiofilm and antimetabolic effects of disinfectants on Pseudomonas aeruginosa strains isolated from cosmetic manufacturing environments

Pseudomonas aeruginosa is a major contaminant in cosmetics, posing significant health risks to consumers. These bacteria form biofilms that protect them from disinfectants commonly used in the cosmetic industry. This study aimed to assess the impact of disinfectants, cleaners, and sanitizers on the metabolic activity and biofilm formation of P. aeruginosa isolated from the production line in a cosmetic manufacturer. In vitro experiments were conducted using silicone, Teflon, ethylene propylene diene monomer and acid-resistant steel surfaces, which are commonly used materials in cosmetic production line equipment. Spectrophotometric methods were used to evaluate biofilm formation and metabolic activity, while different imaging techniques (SEM, EFM, OCT) were employed to visualize biofilm structure directly on examined surfaces. The results showed that hypochlorous acid is the most effective disinfectant in inhibiting biofilm formation. Hypochlorous acid significantly reduced the metabolic activity of P. aeruginosa, particularly in biofilms forming on the surface made of stainless steel. Additionally, the study validated the feasibility of implementing a sterilization method using hypochlorous acid directly in industrial conditions for production line sterilization. Results showed a significant reduction in contamination levels in water passing through the installation, from an uncountable level to below 0.1 × 10¹ CFU mL^-1. In conclusion, the effectiveness of disinfectants in preventing biofilm formation and metabolic activity is dependent on their composition and the type of surface on which the biofilms form. Hypochlorous acid proves to be an effective disinfectant for combating bacterial biofilms in the cosmetic industry. KEY POINTS: The tested strains of P. aeruginosa formed a strong biofilm and were drug-resistant Hypochlorous acid exhibited the highest antibacterial efficacy among the tested agents Hypochlorous acid effectively eliminated biofilm-associated microbes in the facility's water system.