Application of Lactobacillus gasseri 63 AM supernatant to Pseudomonas aeruginosa- infected wounds prevents sepsis in murine models of thermal injury and dorsal excision

. Severely burned patients are susceptible to bacterial infection within their burn wounds, which frequently leads to sepsis, multiple organ failure and death. The opportunistic pathogen , an organism inherently resistant to multiple antibiotics, is a common cause of sepsis in these patients. . Development of a topical treatment unrelated to conventional antibiotics is essential for prevention of infection and sepsis, leading to a role for the direct application of probiotics or their by-products. . We examined the effectiveness of 20× concentrated supernatant from strain 63 AM (LgCS) grown in de Man, Rogosa and Sharpe broth in inhibiting biofilms , as well as in reducing wound bioburden and sepsis . . LgCS inhibited the growth of strain PAO1, prevented its biofilm development and eliminated partially developed PAO1 biofilms. In the murine model of thermal injury, a single injection of LgCS following injury and PAO1 infection reduced mortality to 0 % and prevented systemic spread (sepsis). Furthermore, a second injection of LgCS 24 h after the first eliminated PAO1 from the wound. In the murine dorsal excision infection model, either LgCS or ceftazidime treatment of the PAO1-infected wound significantly reduced the mortality rate among infected mice, while combining LgCS with ceftazidime eliminated mortality. . These results suggest the potential of LgCS in preventing sepsis from infection in severely burned and other immunocompromised patients.