AUTHOR=Ye Zuoji , Ye Liumei , Li Dingbin , Lin Shunsheng , Deng Wusheng , Zhang Li , Liang Jinhua , Li Jinlong , Wei Qingjun , Wang Ke 

TITLE=Effects of daphnetin on biofilm formation and motility of pseudomonas aeruginosa

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.1033540

DOI=10.3389/fcimb.2022.1033540

ISSN=2235-2988

ABSTRACT=<sec><title>Introduction</title><p><italic>Pseudomonas aeruginosa</italic> is a common clinical opportunistic pathogen. Antibiotic resistance of <italic>P. aeruginosa</italic> is frequent, and it affects the clinical curative effect and leads to recurrent infections, disease progression, and difficult treatment, especially in cystic fibrosis patients. The drug-resistance mechanism of <italic>P. aeruginosa</italic> is complex, and biofilms play an important role. Given the widespread antibiotic resistance of <italic>P. aeruginosa</italic>, the discovery of a drug that can prevent or eradicate biofilm formation is imperative. Daphnetin (DAP), a coumarin derivative, is a safe, non-toxic, natural compound with antibacterial and anti-biofilm properties. Herein, this study highlights the bacterial motility effects, antibacterial effect, pyocyanin production, and anti-biofilm potential of DAP against <italic>P. aeruginosa</italic>.</p></sec><sec><title>Methods</title><p>In this study, the minimal inhibitory concentration of DAP against <italic>P. aeruginosa</italic> was determined using the microdilution method. The antibiofilm activity of DAP against <italic>P. aeruginosa</italic> was determined using crystal violet staining, colony-forming unit enumeration, and scanning electron microscopy. The effect of DAP on <italic>P. aeruginosa</italic> motility was detected using the swimming, swarming, and twitching agar plates to measure the diameter of the concentric area.</p></sec><sec><title>Results</title><p>We found that DAP at concentrations of 0.445–1.781 mg/mL and 0.89–1.781 mg/mL can effectively inhibit biofilm formation and eradicate the formed biofilm of <italic>P. aeruginosa</italic>, respectively. DAP reduced pyocyanin production and inhibited bacterial motility of <italic>P. aeruginosa</italic>.</p></sec><sec><title>Discussion</title><p>In conclusion, our results support the conclusion that DAP can effectively eradicate formed biofilm and inhibit biofilm formation, bacterial motility, and pyocyanin production of <italic>P. aeruginosa</italic> and may represent a natural anti-biofilm therapeutic agent.</p></sec>