Genetic and microbiomics approaches allow the monitoring of the growth of Dermatophagoides pteronyssinus cultures and their environmental influences

Dermatophagoides pteronyssinus is cultured in industrial facilities to produce allergen extracts for allergy diagnosis and therapeutic treatment. In these facilities, mite growth and production should be monitored, and exhaustive quality control is mandatory to harvest mites, reach optimal expansion, and avoid potential microbial contamination. In this study, we explored genetic approaches to monitor the growth of five independent D. pteronyssinus cultures. Microbiological studies were performed to characterise the evolution of microbial communities during culture. Finally, we designed a qRT-PCR application to quantify mite populations in the cultures. Our microbiome studies revealed the presence of non-pathogenic bacteria and the absence of Gram-negative bacteria. Despite the variability in microbiome genera at the beginning of the five cultures, the microbiome composition tended to be more homogeneous among the culture batches as mite growth progressed. Specifically, Staphylococcus sp., Virgibacillus sp., and Malassezia sp. appeared to be the most significant taxa involved in culture progression. In summary, we developed a specific method for quantifying and monitoring mite cultures, which could be used to establish an objective method for harvesting mites to manufacture standardised allergen extracts. Additionally, we provide a comprehensive description of the relationship between mites and their symbiotic microorganisms.