Flagellated protozoa detected in Dermatophagoides by light microscopy.

House dust mites (HDM) are arthropods of medical importance due to their relationship with allergic diseases. House dust provides a detrital habitat for these organisms, in which human skin scales are a primary food source. For digestion, wall gut cells elaborate potent proteases. Nevertheless, the observation of flagellated protozoa in intestinal extracts of HDM by light microscopy might contribute to digestive processes in mites, opening a new avenue of research regarding the ecological interactions between mites and these microorganisms in the utilisation of such substrates, as well as with regard to allergic diseases.