In vitro development of histotropic larvae of Oesophagostomum dentatum under various conditions of cultivation

We performed a total of 14 trials to evaluate the culture conditions suited best for the in vitro production of fourth-stage larvae (L4) of Oesophagos tomum dentatum. Chicken embryo extract was shown to be redundant, whereas p ig blood serum, trypticase, liver extract, and yeast extract proved to be i mportant medium ingredients. Development to L4 could be moderately accelera ted by increases of temperature (40 degrees C) and of CO2 concentration (20 % in air), but the total yield of L4 could not be improved. Thus, condition s of 38.5 degrees C and 10% CO2 are recommended for routine application.