ml bacteria were incubated with 5 nm enzyme 5 nm h 2 o 2 and 100 mm nacl in pbs ph 5 5 for 15 min at 37 u00b0 c serial dilutions were immediately spread on agar plates and the colony forming units determined after overnight incubation at 37 u00b0 c statistical analysis the survival study was evaluated using a fisher 39 s exact p test all other data were analyzed with a student 39 s t test significance was accepted at p lt 0 05 myeloperoxidase deficiency increases mortality in the cecal ligation and puncture clp model of sepsis to evaluate the potential role of the myeloperoxidase system in host defense myeloperoxidase deficient mice and a clinically relevant and widely utilized model of intra abdominal infection and sepsis were used in the cecal ligation and puncture clp model the blind ended cecum is ligated and punctured ref 16 releasing intestinal microflora into the abdominal cavity previous studies have demonstrated that 35 45 of wild type mice survive this procedure for longer than 7 days refs 16 18 when myeloperoxidase deficient mice were subjected to clp none of the animals were alive five 5 days after surgery fig1 in contrast 63 of the wild type littermate control mice were alive after five 5 days and 38.