Mites are notorious for being vectors transmitting infectious pathogens and source of
allergens causing allergic conditions in animals and humans. However, despite their huge impact on public health, the virome of mites remains unknown. Here we characterized the virus diversity and abundance of 14 species of medically important mites based on total
RNA sequencing data sets generated in this study as well as those deposited in the Sequence Read Archive (SRA) database. A total of 47 genetically distinct viruses were identified and classified into 17 virus families or virus super-groups, and the viral sequences accounted for as much as 29.67% of total non-rRNA transcriptome in one mite library. The most commonly identified viruses are members of Picornavirales, among which we revealed more than one type of viruses that are evolutionarily related to dicistronic viruses but contain a single open reading frame, thus likely representing a recent example of host (i.e., mite)-related parallel evolution from dicistronic to monocistronic genomic form within the family Dicistroviridae To our best knowledge, this is the first time to perform comprehensive and systematic screening of
RNA virome in medically important mites including house dust mites (HDM). Overall, the
RNA virome identified here provides not only significant insights into the diversity and evolution of RNA viruses in mites, but also a solid knowledge base for studying their roles in human diseases.IMPORTANCE Mites are important group of arthropods that are associated with a variety of human diseases including
scrub typhus and
asthma. However, it remains unclear whether or not mites carry viruses that might play a role in human
infections or allergic disease. In this study, we used a total transcriptomics approach to characterize and compare the complete
RNA virome within mites that are relevant to human health and diseases. Specifically, our data revealed a large diversity, a high abundance, and a flexible genomic evolution for these viruses. Although most of the viruses identified here are unknown to associate with human
infectious disease, the abundant presence of viral RNAs may play an immunomodulatory role in the development of
allergic reactions such as
asthma during environmental exposure to mite
allergens, and therefore provide important insights into the mite-induced
allergy and preparation of mite
allergen vaccines.