Isolation and Characterization of Phages for Phage Therapy.

is a clinically important pathogen causing a variety of antimicrobial resistant infections in both community and nosocomial settings, particularly pneumonia, urinary tract infection, and sepsis. Bacteriophage (phage) therapy is being considered a primary option for the treatment of drug-resistant infections of these types. We report the successful isolation and characterization of 30 novel, genetically diverse phages. The isolated phages span six different phage families and nine genera, representing both lysogenic and lytic lifestyles. Individual phage isolates infected up to 11 of the 18 capsule types tested, and all 18 capsule-types were infected by at least one of the phages. Of the -infecting phages presented in this study, the lytic phages are most suitable for phage therapy, based on their broad host range, high virulence, short lysis period and given that they encode no known toxin or antimicrobial resistance genes. Phage isolates belonging to the and genera were deemed most suitable for phage therapy based on our characterization. Importantly, when applied alone, none of the characterized phages were able to suppress the growth of for more than 12 h, likely due to the inherent ease of to generate spontaneous phage-resistant mutants. This indicates that for successful phage therapy, a cocktail of multiple phages would be necessary to treat infections.