Bacteriophage-embedded and coated alginate layers inhibit biofilm formation by clinical strains of Klebsiella pneumoniae

J Appl Microbiol. 2025 May 2;136(5):lxaf099. doi: 10.1093/jambio/lxaf099.

Abstract

Aims: This study aimed to determine the antibiofilm properties of Klebsiella pneumoniae phages previously isolated from Thai hospital sewage water. Furthermore, we aimed to develop a phage-embedded and coated alginate hydrogel, suitable as a wound dressing or surface coating to prevent K. pneumoniae proliferation and biofilm formation.

Methods and results: The biofilm forming capacity of six clinical K. pneumoniae isolates was determined by means of the crystal violet assay and four strains which exhibited strong adherence were selected for further characterization. Two phages (vB_KpnA_GBH014 and vB_KpnM_GBH019) were found to both significantly prevent (P = <0.0005) and disrupt (P = <0.05) biofilms produced by their K. pneumoniae hosts as determined by optical density readings using the crystal violet assay. Furthermore, alginate layers embedded and coated with phages vB_KpnA_GBH014 and vB_KpnM_GBH019 produced antibiofilm surfaces. Viable counts of recovered biofilms showed that alginate hydrogels containing phage vB_KpnA_GBH014 or vB_KpnM_GBH019 were associated with significantly fewer K. pneumoniae vs. no-phage controls (1.61 × 108 cfu ml-1 vs. 1.67 × 104 cfu ml-1, P = <0.005 and 1.78 × 108 cfu ml-1 vs. 6.11 × 102 cfu ml-1, P = <0.00005, respectively). Confocal microscopy further revealed a significant reduction in the biovolume of biofilms formed on phage embedded and coated alginate hydrogels compared to no-phage controls.

Conclusions: Phages vB_KpnA_GBH014 and vB_KpnM_GBH019 can both prevent and disrupt biofilms produced by clinical isolates of K. pneumoniae. Embedding and coating these phages into alginate produces an antibiofilm matrix which may have promise for coating medical devices or as a wound dressing.

Keywords: AMR; biofouling; multidrug-resistant.

MeSH terms

  • Alginates* / chemistry
  • Bacteriophages* / physiology
  • Biofilms* / growth & development
  • Glucuronic Acid / chemistry
  • Glucuronic Acid / pharmacology
  • Hexuronic Acids
  • Humans
  • Hydrogels
  • Klebsiella Infections / microbiology
  • Klebsiella Infections / prevention & control
  • Klebsiella pneumoniae* / physiology
  • Klebsiella pneumoniae* / virology

Substances

  • Alginates
  • Hydrogels
  • Glucuronic Acid
  • Hexuronic Acids