Abstract:

Abstract:Objective To explore the application of bacteriophage therapy against intestine-derived infection caused by Pseudomonas aeruginosa and to evaluate the potential value of bacteriophages.Methods Phages were isolated and purified by conventional processes.A murine model of intestine-derived infection caused by Pseudomonas aeruginosa was established through administration of ampicillin and cyclophosphamide (CY) by intraperitoneal injection.Animals were divided  into  treatment group Ⅰ (phage administration,1　d before the bacterial challenge),treatment  group Ⅱ (phage administration，5　d after the bacterial challenge),treatment  group Ⅲ (phage administration，10 d after the bacterial challenge) and control group (no phage administration) to evaluate anti-infection efficacy of phage. Results Four strains of lytic phage were isolated from sewage.1　d before the bacteria challenge,oral administration of lytic phages was sufficiently to rescue 70% of the animals compared with control animals (P<0.01).5 d after the bacteria challenge,oral administration of lytic phages was significantly to rescue 80% of the animals compared with control animals (P<0.01).However,10 d after the bacteria challenge,oral administration of lytic phages was only to rescue 10% of the animals(P>0.05).
Conclusion The phage treatment significantly improve the survival rate of mice during the early stage of infection;it suggestes that the phages may serve as an effective agent against bacterial infection.

Key words: Pseudomonas aeruginosa;bacteriophage;anti-infection therapy