Abstract
Aim
Phage therapy has attracted attention as a promising alternative treatment option for biofilm infections.
To establish a successful phage therapy, a comprehensive stock of different phages covering a broad bacterial spectrum is crucial. We screened human and environmental sources for presence of lytic phages against selected bacteria.
Methods
Saliva collected from 10 volunteers and 500 ml of sewage water were screened for the presence of lytic phages active against 20 clinical strains of Staphylococcus aureus and 10 of Escherichia coli, both isolated from patients with prosthetic joint infection. Laboratory strains of methicillin-resistant S. aureus (MRSA)*1 and E. coli*2 were also tested. Screening was performed plaque-assay to detect phages for different strains. Isolated plaques were collected and phages were enriched to determine their activity against their bacterial host strains. The activity of bacteriophages against adherent E. coli and MRSA was evaluated by crystal violet, staining bacterial biofilms grown on glass beads.
Results
Six bacteriophages specific for MRSA were isolated from saliva. Bacteriophages for E. coli strains were isolated from sewage water (n=3) and saliva (n=1). All bacteriophages tested against biofilms of their bacterial host showed a reduction of the total biomass (ranging from 19% to 84%).
Conclusions
Both sewage and saliva samples provided bacteriophages specific against selected bacterial strains. 24h phage treatment of E. coli and S. aureus biofilms lead to a reduction but not to a complete eradication of biofilm.
