Effect of Hyperbaric Oxygaen on Clostridia in vitro and in vivo . ∗

Summary

Exposure of broth cultures of C. perfringens to air or oxygen at 15 pounds per square inch absolute (15 p.s.i.a.) or to oxygen at 30 p.s.i.a. resulted in a marked and equivalent bactericidal effect. Four hour cultures were more susceptible to the bactericidal action of oxygen than 24 hour cultures. The rate of inactivation of C. perjringens by oxygen was decreased by the presence of blood or muscle and was less at 25° than at 37dGC. Exposure to oxygen of C perjringens on the surfaces of agar plates resulted in inhibition of growth on subsequent incubation in an anaerobic environment. Four hour cultures were more susceptible to the inhibitory activity of oxygen than 24 hour cultures and presence of blood in the agar inhibited the antibacterial action of oxygen. Exposure of broth cultures of C. tetani to air or oxygen at 15 p.s.i.a, or to oxygen at 30 p.s.i.a., resulted in a bactericidal effect similar to that observed with C. perjringens.

Mice injected intramuscularly in normal muscle with C. perjringens could be protected against mortality with treatment with oxygen at 45 p.s.i.a. Oxygen also protected against death in experiments in which infusorial earth was injected with C. perjringens into crushed muscle. Variations in the experimental model such as injecting calcium chloride instead of infusorial earth with C. perjringens into normal or crushed muscle eliminated the protective effect of oxygen.