Phytolectin conjugated positively charged fatty acid amide impairs virulence factors and inhibits cross-kingdom biofilm formation of Candida albicans and uropathogenic Escherichia coli

J Appl Microbiol. 2022 Dec;133(6):3252-3264. doi: 10.1111/jam.15535. Epub 2022 Apr 11.

Abstract

Aim: Polymicrobial biofilm encasing cross-kingdom micro-organisms are apparent in medicine, which imposes serious resistance to conventional antimicrobial treatment. The objective of the study was to explore Butea monosperma seed lectin (BMSL) conjugated antimicrobial lipid, 2-((N-[2-hydroxyethyl]palmitamido)methyl)-1-methylpyridin-1-ium iodide (cN16E) to inhibit mixed-species biofilm of uropathogenic Escherichia coli-Candida albicans.

Methods and results: Antimicrobial activity and antibiofilm of cN16E and cN16E-BMSL conjugate (BcN16E) were analysed against single- and mixed microbial cultures. The minimum inhibitory concentration (MIC) indicates that the MIC of cN16E-BMSL conjugate (BcN16E) against cohabiting UPEC-C. albicans was eightfold lower than the cN16E. BcN16E affects membrane integrity to elicit antimicrobial activity. BcN16E inhibits the dual-species biofilm even with 16 times lower MIC of cN16E. BcN16E impairs the biofilm-associated virulence factors which include extracellular polysaccharides, cell surface hydrophobicity, swimming, swarming motilities, hyphal filamentous morphology, curli formation and haemolysin activity. As a proof of concept, we demonstrated BcN16E ability to inhibit dual-species biofilm formation on a urinary catheter.

Conclusion: The study revealed that the BcN16E is better than cN16E in impairing biofilm-associated virulence factors and exerting antimicrobial activity.

Significance and impact of the study: The findings emphasize that phytolectin has the potential to enhance the anti-virulence strategies of antimicrobials against cross-kingdom biofilm-related infections.

Keywords: N-acylethanolamine; anti-virulence; antimicrobial lipid; phytolectin; polymicrobial biofilm.

MeSH terms

  • Amides
  • Anti-Bacterial Agents / pharmacology
  • Anti-Infective Agents*
  • Biofilms
  • Candida albicans
  • Fatty Acids
  • Microbial Sensitivity Tests
  • Uropathogenic Escherichia coli*
  • Virulence Factors

Substances

  • Virulence Factors
  • Amides
  • Fatty Acids
  • Anti-Bacterial Agents
  • Anti-Infective Agents