Potential of phage therapy against uropathogenic antibiotic resistant Escherichia coli biofilms

Abstract

Urinary tract infections (UTIs) are one of the most common bacterial infections in the world. The majority of UTIs are caused by uropathogenic E. coli (UPEC) which tend to live in surface-attached microbe communities, known as biofilms. Urinary tract infections can be cured with antibiotics, generally with good success. However, increased antibiotic resistance has led to a rise of recurrent UTIs and biofilms are in fact known to reduce the effect of antibiotics. One potential alternative to treat such infections in the future is phage therapy, i.e., using viruses that kill bacteria. The aim of this study was to find out how different bacteriophages (phages) can eliminate three different UPEC strains (EC7, EC10, EC38) growing in biofilms. Five different phages were produced for each strain. Biofilms of each strain were grown in the pegs of 96-well plate lids and then further treated with two different concentrations of phage lysates. In the experiment were studied not only the potential of individual phages, but also their combined effect in pairs and in a cocktail of five phages. The results were obtained by measuring the optical density at a wavelength of 600 nm every 30 minutes for 24 hours using Tecan Spark® microplate reader. The study shows that several treatments effectively reduce bacterial growth and thus, proves the potential of phage therapy as an effective novel approach. When the results are further consider together with a parallel antibiotic study, it is clear that phage therapy is a promising alternative for the treatment of bacterial infections, especially when combined with antibiotic treatment.