Cultivation of Neisseria gonorrhoeae under low-oxygen conditions

Sixteen Neisseria gonorrhoeae strains were examined for their abilities to grow under reduced oxygen tension. Low oxygen tensions were developed by evacuation-replacement procedures in which anaerobes and oxidation-reduction indicators were used as controls. All strains survived 96 h in a medium reduced to below -125 mV without visible growth. Detectable growth occurred at 0.05% oxygen, and 33% of normal colony size under air (21% oxygen) was obtained at 0.15% oxygen. Population selection did not determine survival and growth, but carbon dioxide was required. Characteristic colony morphologies were not evident at the lower oxygen concentrations. Colonial variation was not influenced during survival under anaerobic conditions or growth under low oxygen levels (0.15%). Medium differences were not significant affectors. We concluded that N. gonorrhoeae will grow under tensions suitable for anaerobes, and will demonstrate certain modifications of behavior under these conditions.