The Influence of Growth Medium on Axenic Cultivation of Virulent and Avirulent Acanthamoeba 1

Summary

The growth characteristics are described for two strains of pathogenic Acanthamoeba cultured in an axenic, peptone-based medium under aerated suspension conditions. The highly virulent A-1 amebae grew exponentially with a constant generation time of 8–9 hr to densities of 2.5–3.5 × 10⁶ cells/ml. The HN-3 chronically virulent strain, whose growth medium was enriched with serum, exhibited a generation time of 10–11 hr and attained exponential densities of 1–2 × 10⁶ cells/ml. Encystment readily occurred in stationary phase cultures of HN-3 cells, but not in A-1 cultures. A comparison was made of the growth parameters of the pathogenic Acanthamoeba to the nonpathogenic Neff strain cultured under similar conditions.