Growth of Naegleria fowleri in several axenic media.

Growth of Naegleria fowleri under agitated and unagitated culture conditions was compared using axenic media developed by Balamuth, Cerva, Chang and Nelson. Under agitated culture conditions, the best growth was achieved with Nelson medium. Using unagitated cultures. Cerva medium produced the greatest cell yields. The media of Cerva and Nelson are considerably lower in organic nutrients and salt concentration than are the media of Balamuth and Chang. The pH of the media rose during ameba growth with the increases proportional to the amount of growth, i.e. the greater the cell yield the greater the rise in pH. Maximum cell yields varied by 2.5 fold for 10 human isolates of N. fowleri cultured in Nelson medium.