. 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.