Efficacy of a Broad Host Range Lytic Bacteriophage Against E. coli Adhered to Urothelium

Persistent urinary tract infections (UTI) are often caused by E. coli adhered to urothelium. This type of cells is generally recognized as very tolerant to antibiotics which renders difficult the treatment of chronic UTI. This study investigates the use of lytic bacteriophages as alternative antimicrobial agents, particularly the interaction of phages with E. coli adhered to urothelium and specifically determines their efficiency against this type of cells. The bacterial adhesion to urothelium was performed varying the bacterial cell concentrations and the period and conditions (static, shaken) of adhesion. Three collection bacteriophages (T1, T4, and phiX174 like phages) were tested against clinical E. coli isolates and only one was selected for further infection experiments. Based on the lytic spectrum against clinical isolates and its ability to infect the highest number of antibiotic resistant strains, the T1-like bacteriophage was selected. This bacteriophage caused nearly a 45% reduction of the bacterial population after 2 h of treatment. This study provides evidence that bacteriophages are effective in controlling suspended and adhered cells and therefore can be a viable alternative to antibiotics to control urothelium-adhered bacteria.