S. Schulz (a), Z. Zamora (b), S. Menéndez (b), R. Mutters (a), M. Bette (a)
(a) Veterinary Service, Institute of Medical Microbiology and Institute of Anatomy and Cellular Biology of the Philipps-University of Marburg/L, Germany. (b) Ozone Research Center of Havana, Cuba.

The purpose of this study was, first, to demostrate some effects of intraperitoneally ozonized oxygen application on the course of lethal septic peritonitis, and second, if it is beneficial, to combine ozone (pre-treatment) with different immunomodulating antibiotics. Ozone has complex actions on biological systems like that on the immunsystem, thus modulating the cytokine production/release, which could be beneficial or detrimental on the outcome of survival in the model of lethal peritonitis in rats. Ozone is a substance with a well-known microbiocidal activty in vitro, but hitherto there are no, or only few in vivo studies with ozone in the model of a polymicrobial septic peritonitis. From experiment 1 (ozone-pretreatment: -5 to -1 d) (groups A-E): the survival rate was highest in 56 % (E) in those previously treated with 10 m g/mL ozone; in 34 % (D) in those having received 50 m g/mL ozone, and 23 % (C) in those with 100 m g/mL in comparison to 5 % (A) in untreated rats, or in 16 % (B) treated with medical oxygen. Experiment 2 and 3 (ozone + antibiotic: -5 d to -1 d + 0h + 1h ) (group F-U): the survival rate for ozone + Cefodizine was 66 and 56 % in direct comparison to Cefodizine with 0 % survival, for ozone + Cefatoxime it was 56 and 78 % vs 23 and 17 % without ozone pretreatment; the survival rate for ozone +Levofloxacin was 89 and 56 % vs 12 and 22 % without ozone, and for ozone +Piperacillin/Tazobactam it was 100 and 78 % vs 0 % survival without ozone. Ozonized oxygen might help to prevent lethal peritonitis (prophylaxis). Furthermore, it enhanced the effectivity of different antibiotics significantly. If ozone can also be used as a new strategy to treat a polymicrobial sepsis is now under investigation.