Hydroquinine Enhances the Efficacy of Contact Lens Solutions for Inhibiting <i>Pseudomonas aeruginosa</i> Adhesion and Biofilm Formation

• Main Authors: Sattaporn Weawsiangsang (Author), Nontaporn Rattanachak (Author), Sukunya Ross (Author), Gareth M. Ross (Author), Robert A. Baldock (Author), Touchkanin Jongjitvimol (Author), Jirapas Jongjitwimol (Author)
• Format: Book
• Published: MDPI AG, 2024-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antibiotics13010056; 2079-6382
• Keywords: adhesion; biofilm; contact lens solution; hydroquinine; microbial keratitis; <i>Pseudomonas aeruginosa</i>; Therapeutics. Pharmacology; RM1-950
• Source: Antibiotics, Vol 13, Iss 1, p 56 (2024)

<i>P. aeruginosa</i> is one of the most common bacteria causing contact lens-related microbial keratitis (CLMK). Previous studies report that disinfecting solutions were ineffective in preventing biofilm formation. Solutions containing novel natural agents may be an excellent alternative for reducing the risk of CLMK. Here, we investigate the disinfecting properties of hydroquinine in combination with multipurpose solutions (MPSs) to prevent <i>P. aeruginosa</i> adhesion and biofilm formation. We examined the antibacterial, anti-adhesion, and anti-biofilm properties of hydroquinine-formulated MPSs compared to MPSs alone. Using RT-qPCR, hydroquinine directly affected the expression levels of adhesion-related genes, namely, <i>cgrC</i>, <i>cheY</i>, <i>cheZ</i>, <i>fimU</i>, and <i>pilV</i>, resulting in reduced adhesion and anti-biofilm formation. Using ISO 14729 stand-alone testing, hydroquinine met the criteria (>99.9% killing at disinfection time) against both <i>P. aeruginosa</i> reference and clinical strains. Using the crystal violet retention assay and FE-SEM, MPSs combined with hydroquinine were effective in inhibiting <i>P. aeruginosa</i> adhesion and destroying preexisting biofilms. This report is the first to highlight the potential utility of hydroquinine-containing formulations as a disinfecting solution for contact lenses, specifically for inhibiting adhesion and destroying biofilm. These findings may aid in the development of novel disinfectants aimed at combating <i>P. aeruginosa</i>, thereby potentially reducing the incidence of CLMK.