Cocktail therapy to inhibit multispecies biofilm in cystic fibrosis patients

(1) Plano East Senior High School, Plano, Texas, (2) University of California, Berkeley, California, (3) Massachusetts Institute of Technology, Cambridge, Massachusetts

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Bacterial biofilms cause 80% of life-threatening chronic infections such as urinary tract infections, wound infections, indwelling catheter infections, and severe pneumonia in immunocompromised patients such as those with cystic fibrosis (CF). ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter) pathogens are known to form dense biofilms highly resistant to antibacterial treatments. This can lead to antibiotic use at higher concentrations, resulting in antibiotic resistance and toxicity. Furthermore, biofilms exist in a dense multispecies form where they communicate with each other by a mechanism called Quorum Sensing (QS), making them hostile to several antibiotics. The focus of our project was to use a combination treatment consisting of FDA-approved concentrations of three different Quorum Quenching (QQ) agents that specifically target the QS mechanisms between the three major interspecies biofilm-pathways within the CF lung: chlorogenic acid to inhibit Pseudomonas fluorescens-Staphylococcus epidermidis signaling, carvacrol to inhibit P. fluorescens-Burkholderia pyrrociniaP. fluorescens-Candida albicans signaling. Computational analysis of the CF lung microbiome using QIIME2 and PICRUSt2 confirmed the necessity of QS in multispecies biofilm pathways. Docking analysis further supported the binding affinities of each treatment and targeted enzymes. The combination treatment demonstrated a near 80% efficacy in inhibiting P. fluorescens-S. epidermidis-B. pyrrocinia-C. albicans biofilm. Treatment safety was supported by a cytotoxicity assay on human alveolar epithelial cells. These findings can be translated into developing novel adjuvants to deliver the cocktail treatment in vivo, thus reducing morbidity and mortality from chronic biofilm-related infections and saving millions of dollars in product decontamination.

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