Survival of T. pallidum under microaerobic conditions in cell and tissue cultures

The survival of pathogenic T. pallidum was studied under microaerobic conditions (partial pressure of oxygen 7 mm Hg) with and without tissue cell cultures. As between one third and half of the germs were motile even after 96 hours of incubation, treponemes do not seem to be strictly anerobic as has been generally believed so far. Flocks containing enormous numbers of treponemes were observed in the nutrient medium. For their formation, human serum, testicular components from rabbits and modified Nelson's survival medium were essential. Although the problem of cultivation of T. pallidum remains to be solved the formation of flocks indicates a possible transient multiplication of treponemes in vitro.