BACTERIOPHAGE M13 MODULATES THE SEPSIS-RELATED INFLAMMATORY RESPONSES AND ORGAN DAMAGE IN A CLP MODEL

Background: Sepsis is a life-threatening disorder that leads to the induction of inflammatory responses and organ failure. Phage therapy is a new approach to controlling infections resistant to common treatments, including sepsis. Several studies have shown the effect of lytic bacteriophages on infection control by reducing the bacterial load. The present study deals with lysogenic bacteriophage M13 on the inflammatory responses caused by cecal ligation and puncture (CLP)-induced sepsis in a mouse model. Methods Bacteriophage M13 harvested from ER2738, titrated, and confirmed by transmission electron microscopy analysis. In vitro toxicity and immunomodulatory effect of bacteriophage M13 were assessed on splenocytes by measurement of cell viability and the production level of cytokines, nitric oxide, and reactive oxygen species. For in vivo experiments, 8-weeks-old male C57BL/6 mice were randomly divided into the following three groups: CLP + NS (treated with normal saline), CLP + M13 (treated with an intraperitoneal injection of 10 9 PFU/mL of bacteriophage M13), and sham + NS (induced surgery but without ligation and puncture, treated with NS). The mice were killed at different time points after surgery (6, 24, 48, and 72, n = 10 for each time point of each group). The kidney, liver, and lungs were harvested for histopathological analysis, and blood was obtained for cytokine and liver enzyme assay. The spleen was used to assess the bacterial load using colony-forming unit assay. The rectal temperature and survival were evaluated during the study. Results According to the in vitro results, 10 9 PFU/mL of bacteriophage M13 was not toxic and did not affect the level of cytokine, nitric oxide, and reactive oxygen species production by splenocytes, but it reduced the inflammatory response of splenocytes in responses to LPS. In vivo studies indicated that the amount of proinflammatory cytokines, liver enzymes, bacterial load, and organ failure were decreased in the CLP + M13 group compared with CLP + NS, whereas the survival rate was increased. Conclusions These experiments demonstrated that bacteriophage M13 could lessen the consequences related to sepsis in CLP mice and can be considered a therapeutic approach in sepsis.