An experimental mouse model for phage therapy of bacterial pathogens causing bacteremia.

A minimum lethal dose on mice for five bacterial pathogens were identified with PCR of neonatal septicemia of Escherichia coli, Klebsiella pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, Citrobacter freundii and Moraxella catarrhalis were studied. Bacteriophage preparations active against 10 isolates of E. coli, 10 isolates of K. pneumoniae, 4 isolates of H. influenzae, 3 isolates of P. aeruginosa, 1 isolate of C. freundii and 1 isolate of M. catarrhalis were tested for their efficacy in treatment of experimental mouse bacteremia of those isolates through dose-ranging and delayed-treatment studies. Efficacy of polyvalent phage preparations of different phages belonging to same species against pathogens of the same species was studied. Results showed that monovalent and polyvalent phage preparations were active in treatment of mice bacteremia after 45 min of injection of bacterial pathogens and on intervals of 5 h, 8 h, 14 h, 18 h and 24 h after bacterial pathogen injection.