Quantitative cidal activity of hyperbaric oxygen for opportunistic yeast pathogens
Bornside, G.H.
Aviation Space and Environmental Medicine 49(10): 1212-1214
1978
ISSN/ISBN: 0095-6562 PMID: 568466 Document Number: 124658
Cidal activities of 24 h exposures to 100% oxygen and 95% oxygen + 5% carbon dioxide were assayed at 1 and 3 ATA. Twenty one yeasts isolated from humans (Candida albicans (8 strs), C. tropicalis (3), C. parapsilosis (2), C. krusei (3), C. guilliermondii (2) and 1 each of C. pseudotropicalis, C.stellatoidea and Torulopsis sp.) were all extremely sensitive to hyperbaric oxygen although sp. and str. differences were observed. Indices of kill from 80-100 (total kill) characterized 17 of the 21 yeasts (81%). Hyperoxia (oxygen plus or minus carbon dioxide at 1 ATA) was not lethal. Carbon dioxide deprivation as a consequence of hyperbaric exposure to 100% oxygen enhanced cidal activity for only 2 yeasts whereas hyperbaric exposure to the mixture enhanced activity against 4. Cidal activities were not significantly different for the remaining 15. This response to carbon dioxide deprivation was different from that of bacteria and manifests fundamental differences between procaryotic and eucaryotic cells.