Biological Properties of Oncospheres of Echinococcus spp.

Document Type : Original Article


All-Russian Scientific Research Institute for Fundamental and Applied Parasitology of Animals and Plant-a branch of the Federal State Budget Scientific Institution “Federal Scientific Centre VIEV”, A117218 Moscow, B. Cheremushkinskaya St., 28, Moscow and 117218, Russia


Introduction: Taeniasis is known as a global human and animal parasite. Infestation by Echinococcus has significantly decreased in some countries as a result of modern research aiming to combat this type of tapeworm. To obtain protective biologics, biomass of inactivated material is required. The present study aimed to obtain the maximum number of oncospheres of the genus Echinococcus for the preparation of vaccines.
Materials and methods: Echinococcus multilocularis (E. multilocularis) eggs were placed in artificial intestinal juice. A beaker with juice and eggs was placed on a heated magnetic stirrer. To test the biological properties of the culture, Echinococcus eggs were used for infection of the laboratory mice. For infection, four groups of mice were used. Echinococcus eggs were activated in artificial intestinal juice on a magnetic stirrer in the first group. In the second group, cestode eggs were activated under thermostat conditions (38°C) in artificial gastric and, then, in intestinal juice. The third group was a positive control. The last group was a negative control. The selection of E. multilocularis metastases in laboratory mice was performed for 13 months. Cestodes parasitic cysts were evaluated in each infected mouse at the end of the experiment. The physiological status of E. multilocularis cysts in mice was assessed by a helminthological autopsy. The viability and activity of E. multilocularis protoscoleces were evaluated by motor activity. Mobility was recorded when heating the samples at 37°C for 10-15 minutes.
Results: In the first group, second, and positive control groups, 70%, 44.4%, and 33.3% of the mice were sensitive to the alveococcus causative agent, respectively. The larval cysts of the cestodes were identified in the liver and lungs of the mice in the first experimental group. In the second and third groups, the larval in the form of the alveococcus was identified only in the liver.
Conclusion: This method allows the investigation of the main biological indicators of cestode egg culture (viability, invasive activity). The novelty of the method is using only artificial intestinal juice without artificial gastric juice. The method can increase yield of activated oncospheres in a short period of time.