Growth of Nosema cuniculi in established cell lines.

Growth patterns of Nosema cuniculi (Encephalitozoon cuniculi) in cell cultures of bovine kidney, canine kidney, feline lung, and rabbit kidney were studied. All cell cultures used were easy to manage and the last 3 are commercially-available established cell lines. The dog kidney cells were the most suitable for large-scale production of Nosema. When grown in plastic flasks with a bottom area of 75 cm2, the weekly yield from Nosema-infected canine kidney cells during the 10th to 17th week after inoculation was between 4-1 times 10-7 and 9-9 times 10-7 spores per flask. An equilibrium was obtained between the Nosema infection and the kidney cells during this time. A simple method for estimating the number of harvested spores is also described.