Mahboubeh Soleimani Sasani - Department of microbiology and microbial biotechnology, faculty of life sciences and biotechnology, Shahid Beheshti University , Tehran, Iran
Fereshteh Eftekhar - Department of microbiology and microbial biotechnology, faculty of life sciences and biotechnology, Shahid Beheshti University , Tehran, Iran

Background and Aim:Multidrug-resistant Klebsiella pneumonia, which is very common in hospital environments, causes infections in humans especially in immunocompromised patients. Phage therapy, which is an alternative antibacterial therapies, is now under serious consideration and one possible option therapies to treat bacterial infections. In our study, we isolated a lytic bacteriophage from wastewater sample and study the ability of bacterial viruses to treat mice challenged with K. pneumoniae.Methods:A specific phage with lytic activity for K. pneumoniae ATCC10031 was isolated from sewage samples and characterized, and its potential as a therapeutic agent was evaluated in an experimental model of K. pneumoniae-mediated lobar pneumonia in mice. Mice were challenged by intranasal inoculation(i.n) with bacteria (108CFU/ml). A single intraperitoneal injection of 1010PFU/ml (MOI 100) and 109PFU/ml (MOI 10) of isolated phage administered immediately after i.n. In 2 groups, injection of this phage was delayed up to 24 h post infection and phage and bacterial numbers counting in mice blood and lungs after mice euthanasia.Results:The results of this study suggest that Treatment by a single injection of Phage simultaneous with bacterial infection and Delayed Phage Treatment, clearance of bacteria from the mice can obtain due to phage therapy. This phage thus have the potential to be used for phage therapy. Surveys of bacterial counts for mice treated with isolated phage by the intraperitoneal route (in MOI 10 and 100) provided significant protection in infected mice from both blood and lungs tissue.Conclusion:These results demonstrate the isolated phage can be used for the treatment of K. pneumoniae infections.

Bacteriophage, lung infection, Klebsiella pneumoniae, lobar pneumonia