The effect of hyperbaric oxygenation on experimental Bacteroides fragilis infection in the rat liver

An experimental intra-abdominal model for producing Bacteroides fragilis abscesses in the rat liver was used to evaluate the therapeutic effect of hyperbaric oxygenation (HO) at 3 ATA (atmospheres absolute). Two different experiments were performed. In the first experiment one half of the animals were inoculated with B. fragilis, and the other half were sham-operated. Whether the inoculated or sham-operated animals were given single or repeated HO treatment at 3 ATA for 90 min, the bacteriological pattern was about the same. In the second experiment all the animals were inoculated with B. fragilis; half of the animals were given HO at 3 ATA for 90 min as single or repeated treatments, and the other half acted as controls receiving no HO. Even if the HO treatment was given every day during 21 days, B. fragilis could be recovered in all inoculated animals 22 days after inoculation.