The Efficacy of Topical Bacteriophage Semisolid Preparation on Burn Wounds Infected by Pseudomonas Aeruginosa

Abstract Objective: Recently, antibiotic resistance of post-burn infections caused by opportunistic pathogens, Pseudomonas aeruginosa, became complicated due to its innate and acquired resistance. Bacteriophage therapy containing virulent factors that infect their specific host bacteria can be evaluated as an alternative treatment.In this study,the topical formulation contains lytic phages compared to the antibioticinthe murine model of burn/infected wound healing.Methods & Materials: Lytic bacteriophages were extracted from hospital sewage and propagated in broth culture of P.aeruginosa(24 hours, 37°C) and subsequently filtered.The collected phages were recultured alongside P. aeruginosa. The plaques were observed as clear zones and added to the polyethylene glycol (PEG) base ointment. Twenty-four adult female mice were selected and divided into four groups. Asecond-degree burn wound wascreated on the back of the mice and infected with 100 microliters of 1×102 - 3×102 CFU/ml P. aeruginosa subcutaneously. After 24 hours, each group received one of these interventions: silver sulfadiazine, ointment contains bacteriophage, ointment without bacteriophage (PEG group),or no treatment. Burn wound size, physical activity, and body temperature (rectal) were recorded every other day. On the 10th day, mice were sacrificed through cervical dislocation. Thewound’s skin was cut and evaluated histopathologically.Results: Significant differences inthe burn wound sizeamongthe bacteriophage groupversus the PEG group, the bacteriophage group versus the no-treatment group, and the antibiotic group versus the PEG group (P= 0.001, P= 0.001, P= 0.002 respectively)were observed. Mice’s physical activity was gradually improved in all groups and showed significant differences (P<0.001). Body temperature analyses showed significantdifferences only when day 8th compared with day 2nd, 4th, and 6th (P=0.001, P=0.02, P=0.02 respectively). Histopathological results indicated optimal wound healing in both the antibiotic group and bacteriophage group. However, no significant differences were observed in microscopic histopathological criteria in any groups based on Fisher’s exact statistical tests.Conclusion:Formulated phage ointmenteffectivelyprevents and treats burn wound infection in mice with no allergic reactions.