Diet Influences Growth Rates and Allergen and Endotoxin Contents of Cultured <b><i>Dermatophagoides farinae</i></b> and <b><i>Dermatophagoides pteronyssinus</i></b> House Dust Mites

Abstract

Background: The house dust mites Dermatophagoides farinae and Dermatophagoidespteronyssinus are cultured to obtain material for the production of allergen extracts for research, diagnostic and immunotherapeutic purposes. Methods: We cultured mites on two different diets that supported thriving populations and determined the population growth rates, dynamics of allergen accumulation, and endotoxin concentrations in extracts made from mites harvested from the cultures. Results:D. farinae populations grew faster on a diet of rodent chow/yeast than on an egg/yeast diet but a larger peak population size was achieved on the egg/yeast diet. Diet influenced the dynamics of the production of groups 1 and 2 allergens and the group 1/2 ratios for both species. To population peak, Der f 1 was produced at a faster rate on the chow/yeast diet but greater amounts of Der f 1 were produced by mites grown on the egg/yeast diet. D. pteronyssinus populations grew faster and achieved greater density on the egg/yeast diet compared to the chow/yeast diet. D. pteronyssinus produced more Der p 1 than Der p 2 when grown on chow/yeast while more Der p 2 than Der p 1 was produced on egg/yeast. Endotoxin concentrations in extracts made from whole cultures for both species at maximum population density were very different in the two diets. Washing the mites resulted in the loss of up to 88% of the allergen. Conclusion: Mite-culturing diet directly effects population growth, the dynamics of allergen accumulation, the group 1/2 allergen ratio and the endotoxin contents in extracts of cultured house dust mites.

Quality Control of House Dust Mite Extracts for Allergen Immunotherapy

“…the spectrum of major and minor allergens) is known to vary depending upon both the nature of the source materials used to prepare the extracts (e.g. mite bodies vs. whole mite cultures) and the culture process [3,4]. This challenge is made even more complex when considering that an ideal product for house dust mite immunotherapy should combine both D. pteronyssinus and D. farinae extracts.…”

Towards a More Complete Standardization of Mite Allergen Extracts

“…In summary, the article by Avula-Poola et al [5] clearly shows important differences when mites are grown on dissimilar media. It also shows that differences in endotoxin and major allergen content are also a consequence of differences in the diet.…”

“…The study by Avula-Poola et al [5] demonstrates that D. farinae and D. pteronyssinus cultures grow at different rates. They also demonstrate that rates of accumulation and the amounts of group 1 and group 2 allergens and the levels of endotoxin in mite cultures, and in the extracts prepared from them, are dramatically influenced by the foods on which the mites were grown.…”

Population Growth and Allergen Content of Cultured <b><i>Euroglyphus maynei</i></b> House Dust Mites

“…The methods used for these studies were similar to those previously described for D. farinae and D. pteronyssinus [24][25][26] . Briefly, 5 replicate test cultures were started in one-cup glass Ball ® jars (Cat.…”

“…farinae and D. pteronyssinus are widely cultured for research and commercial purposes, but E. maynei is not and is generally not commercially available, especially in the US. The population growth and associated allergen and endotoxin profiles of cultured D. farinae and D. pteronyssinus have been described [24][25][26][27][28][29][30][31][32][33][34][35] . However, there are little data that characterize the population growth in cultured E. maynei mites and the parallel allergen production and endotoxin accumulation in these cultures.…”