부산대학교 도서관

Background: Sarcoptes scabiei is a permanent obligate ectoparasite that lives and reproduces in the epidermis of humans and other mammals worldwide. There is a lack of information on the molting process of Sarcoptes scabiei. Ivermectin is widely used to treat Sarcoptes infection in humans and animals, while the survival of molting Sarcoptes mites in the presence of ivermectin is unknown. The aim of the present study is to investigate the molting process of Sarcoptes mites and assess the activity of ivermectin during the molting process of Sarcoptes mites. Methodology/Principal findings: molting Sarcoptes mites were incubated at 35°C and 80% relative humidity and observed hourly until complete molt. Of the 192 molting mites recorded, the longest molt periods for larvae and nymphs were 23 and 30 h, respectively. The activity of ivermectin on molting Sarcoptes mites was also assessed using two concentrations of the drug (0.1 and 0.05 mg/ml). The exposure time for molting mites was determined by 100% mortality of female mites exposed to the solution of ivermectin. While all female mites were killed after exposure to 0.1 mg/ml ivermectin for 2 h and and 0.05 mg/ml for 7 h, 32% and 36% of molting mites survived and successfully molted, respectively. Conclusions/significance: The present study demonstrated that molting Sarcoptes mites are less susceptible to ivermectin than active mites. As a consequence, mites may survive after two doses of ivermectin given 7 days apart due not only to hatching eggs but also to the resistance of mites during their molting process. Our results provide insight into the optimal therapeutic regimens for scabies and highlight the need for further research on the molting process of Sarcoptes mites. Author summary: Sarcoptes scabiei is a permanent obligate ectoparasite causing contagious disease in humans and other mammals worldwide. Sarcoptes mites undergo three molts in their lifetime, however, there is limited information on their molting process. Oral ivermectin is widely used for the treatment of Sarcoptes infection in humans and animals. To investigate whether ivermectin is active against molting Sarcoptes mites, we first explored the molting process of Sarcoptes mites in vitro, and then assess the activity of ivermectin. We demonstrated that the average molt period lasts for about 2 days. When exposed to ivermectin, one-third of molting mites survived whereas all active mites died. The present study suggests that mites may survive after two doses of ivermectin 7 days apart due to the resistance of mites during the molting process. [ABSTRACT FROM AUTHOR]