Establishment And Evaluation Of Culture System For Psoroptes Cuniculi In Vitro

Psoroptes cuniculi belongs to Psoroptes and Psoroptidae, and is mostly parasitic on theskin of animal. They have a strong ability of adapting to the environment and rapidlyreproduction with serious damage. Psoroptes cuniculi is mainly parasitic in the ear canal ofrabbit and feeds on their blood and tissue fluid. Local inflammation and severe itching wouldtake place after infected, and the animal shows signs of depression and body weight lossbegan, and gets sicker because of secondary infection. But, at present, the most studies onPsoroptes cuniculi focus on morphology, epidemiology, prevention and cure technology, thereare few reported about the growth factor and culture in vitro. Nowadays, the acarid forstudying must obtain from rabbit, not only inconvenient for operation, but also low onreproducibility for the inconformity of the developmental stage of mite. Through thescreening study on conditions and nutrient medium for Psoroptes cuniculi in vitro, the resultswere as follows:（1）Optimization of the Culture Conditions for Psoroptes cuniculi in vitro: Orthogonalexperiment was adopted to optimize the best culture condition in vitro which was designedwith the survival rate and the longest survival time of Psoroptes cuniculi as the evaluationindexes. The results showed that the factors affecting the survival rate of Psoroptes cuniculiwere temperature> relative humidity> pH, the optimum conditions were as follows:temperature18℃, relative humidity95%and pH6~8. Under these conditions, the averagesurvival rate of Psoroptes cuniculi was86.6%at70h, and the longest survival time was morethan220h. The low temperature and high humidity are conducive to the growth of Psoroptescuniculi, and they have tolerance to pH value.（2）Optimization of the Culture Medium for Psoroptes cuniculi in vitro: Single factorand orthogonal experiments were adopted to optimize the culture medium in vitro which wasdesigned with the evaluation index of the survival rate. The result showed that the influencingfactors in turn were sodium chloride, glucose, peptone, beef extract, the best culture mediumwas as follows:1.5%of beef extract,1.5%of peptone,1.5%of glucose,0.25%of sodiumchloride,0.5%of yeast extract. On this culture medium, the average survival rate of the Psoroptes cuniculi was89.9%at93h, and the longest survival time was more than240h.