A successful method for mass culture of the house dust mite, Dermatophagoides pteronyssinus (Troussart, 1897)

Abstract

Comparative studies have been carried out to find out an optimum condition for efficient mass culture of Dermatophagoides pteronyssinus (Troussart, 1897), the most dominant species of the house dust mites. Among various food materials tested for culture media, the mixture composed of 2 parts of powdered laboratory animal food, 2 parts of dried yeast and 1 part of dried fish powder was found to be most fitted. The humidity content of the medium was best when adjusted to 16% beforehand and thin layer of the food medium was prepared in Roux's-bottle with a paper plug. The plug of the bottle was opened once a week and the medium was mixed thoroughly by shaking to prevent clotting. When about 15,000 mites were inoculated into 100 g of culture media, the highest yield was obtained with relative humidity regulated at 75% and the temperature at 25 degrees C after 12 weeks of incubation. Purified mites were separated from culture media by floatation with saturated NaCl solution and the average yield of the mice was 2 to 3 g in wet weight per 100 g of the food mixture.