Antimicrobial Synergy: Biocides and QSIs for UTI Prevention

What is it about?

The study aimed to evaluate the combinatorial impact of biocides and QSIs at bacteriostatic, bactericidal, and biofilm eradication concentrations in parallel to assessing cytotoxicity in a bladder smooth muscle cell line. Checkerboard assays were performed to determine fractional inhibitory, bactericidal, and biofilm eradication concentrations of test combinations in UPEC and combined cytotoxic effects in BSM cells. Synergistic antimicrobial activity was observed between polyhexamethyline biguanide, benzalkonium chloride or silver nitrate in combination with either cinnamaldehyde or furanone-C30 against UPEC biofilms. PHMB and silver in combination with cinnamaldehyde display synergistic antimicrobial activity in UPEC at non-cytotoxic concentrations, suggesting potential as anti-infective catheter-coating agents.

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Why is it important?

The research is important because it evaluates the combinatorial impact of biocides and quorum sensing inhibitors (QSIs) on antimicrobial activity against uropathogenic Escherichia coli (UPEC), which is a primary cause of catheter-associated urinary tract infections (CAUTIs). The study aims to find potential anti-infective catheter-coating agents to prevent CAUTIs. Key Takeaways: 1. The study found synergistic, additive, and antagonistic interactions between biocides and QSIs at bacteriostatic, bactericidal, and biofilm eradication concentrations. 2. PHMB and silver in combination with cinnamaldehyde displayed synergistic antimicrobial activity against UPEC at non-cytotoxic concentrations, suggesting potential as anti-infective catheter-coating agents. 3. The test biocides and QSIs have various growth inhibitory and bactericidal modes of action that may account for the synergism observed at bacteriostatic and bactericidal concentrations.