Safety and efficacy of a bacteriophage cocktail in an in vivo sinusitis model

The objectives of this study were to evaluate the safety and efficacy of a Pseudomonas aeruginosa (PA) phage cocktail in a sheep model of rhinosinusitis. The sheep rhinosinusitis model was adapted to simulate a PA infection in the frontal sinuses of the sheep. To assess efficacy, following a 7-day biofilm formation period, the sheep received a rinse with either the phage cocktail or a saline solution twice daily for one week. Biofilm quantification on the frontal sinus mucosa was performed using LIVE/DEAD BacLight staining.

To assess safety, a second control group of sheep received a rinse with the phage cocktail twice daily for 3 weeks. Blood and stool samples were collected throughout the treatment. Tissue samples were taken from the frontal sinus, lungs, heart, liver, spleen, and kidney tissue and examined using scanning electron microscopy (SEM).

A significant reduction in biofilm was observed in the sheep treated with the phage cocktail. The phages could still be detected in the frontal sinuses 16 hours after the rinse.

The second control group of sheep received a rinse with the phage cocktail for 3 weeks. Phages were consistently detected in the stool and sporadically in blood and organ samples. No tissue damage was found during the examination of the tissue samples. In summary, the phage cocktail was able to reduce the biofilm in the frontal sinus by 10^8-10^10 PFU/mL.

Fonga SA, Drillinga AJ, Ooia ML et al. Safety and efficacy of a bacteriophage cocktail in an in vivo model of Pseudomonas aeruginosa sinusitis // Translational Research, Available online 19 December 2018 https://doi.org/10.1016/j.trsl.2018.12.002