Therapeutic potential of bacteriophage in treating Klebsiella pneumoniae B5055-mediated lobar pneumonia in mice

Abstract

Klebsiella pneumoniaecauses infections in humans especially in immunocompromised patients. About 80 % of nosocomial infections caused byK. pneumoniaeare due to multidrug-resistant strains. The emergence of antibiotic-resistant bacterial strains necessitates the exploration of alternative antibacterial therapies, which led our group to study the ability of bacterial viruses (known as bacteriophages or simply phages) to treat mice challenged withK. pneumoniae. Phage SS specific forK. pneumoniaeB5055 was isolated and characterized, and its potential as a therapeutic agent was evaluated in an experimental model ofK. pneumoniae-mediated lobar pneumonia in mice. Mice were challenged by intranasal (i.n.) inoculation with bacteria (108 c.f.u. ml−1). A single intraperitoneal injection of 1010 p.f.u. ml−1phage administered immediately after i.n. challenge was sufficient to rescue 100 % of animals fromK. pneumoniae-mediated respiratory infections. Administration of the phage preparation 3 h prior to i.n. bacterial challenge provided significant protection in infected mice, while even 6 h delay of phage administration after the induction of infection rendered the phage treatment ineffective. The results of this study therefore suggest that the timing of starting the phage therapy after initiation of infection significantly contributes towards the success of the treatment.