In vitro culture and morphological observation of human eye demodex mites

The prevalence of human Demodex mites has surged in recent years, prompting significant concern among both patients and the medical community. This study aimed to investigate the survival duration and morphological alterations of Demodex folliculorum under diverse temperature conditions and in various culture media. We employed the eyelash sampling technique to procure the mites. The collected specimens were then subjected to culture at two distinct temperature ranges (16-22 °C and 4 °C) across a spectrum of media, including 30% tea tree oil (TTO), phosphate-buffered saline (PBS), pure water, 0.9% physiological saline, 5 µg/ml propidium iodide (PI), liquid paraffin, glycerol, and a blank culture medium. Post-administration, the mites' activity and morphological changes were meticulously documented. Our findings indicate that the survival span of Demodex mites within the same medium was notably extended at 4 °C compared to room temperature. Specifically, under 4 °C, the use of liquid paraffin as a culture medium yielded the longest survival time of 12 days, surpassing all other conditions. Remarkably, the morphological integrity of the mites in this group remained largely unaltered. These results suggest that 4 °C is the optimal temperature for the in vitro cultivation of Demodex mites, offering insights into the environmental preferences of these organisms and potentially informing future therapeutic strategies.