Anti-infective properties of Lactobacillus fermentum against Staphylococcus aureus and Pseudomonas aeruginosa

J Mol Microbiol Biotechnol. 2011;20(3):137-43. doi: 10.1159/000328512. Epub 2011 Jun 24.


Surgical wounds and implant-associated Staphylococcus aureus and Pseudomonas aeruginosa infections are often difficult to treat because of limited susceptibility of several of these strains to conventional antibiotics. As a result, there is a constant need for new alternative drugs. The aim of this study was to investigate the antimicrobial properties of Lactobacillus fermentum, a probiotic bacterium, which we have isolated from colonic biopsies. The inhibition of S. aureus and P. aeruginosa growth was evaluated by coincubating with L. fermentum strains. Growth inhibition was tested for several of their clinical isolates using agar well diffusion assays. For biofilm assay S. aureus and P. aeruginosa were grown on the glass slides and in 96-well plates in presence of 2.5 μg/ml culture filtrate of L. fermentum. Biofilms were photographed using confocal microscope or stained with 0.1% crystal violet. Reduction in the cytotoxicity of S. aureus and P. aeruginosa was observed in presence of 2.5 μg/ml L. fermentum-spent media. Using in vitroexperiments, we showed that L. fermentum-secreted compound(s) inhibits the growth, cytotoxicity and biofilm formation of several S. aureus and P. aeruginosa strains. Compound(s) present in the culture supernatant of L. fermentum may have promising applications in treating hospital-acquired infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biofilms
  • Cell Line, Tumor
  • Community-Acquired Infections / microbiology
  • Community-Acquired Infections / therapy
  • Humans
  • Lactobacillus fermentum / physiology*
  • Membrane Proteins / metabolism
  • Probiotics
  • Pseudomonas aeruginosa / physiology*
  • Staphylococcus aureus / physiology*


  • Membrane Proteins