Establishment of primary cystic echinococcosis in laboratory mice: our results in the Balb/c strain

BACKGROUND: Establishment of experimental cystic echinococcosis (CE) in laboratory mice is required for the study of CE. Experimental CE may be established in primary or secondary forms; however, the primary form is more reliable for the study of CE. AIMS: The aim of the study was to assess the possibility of establishment of primary CE in Balb/c mice via the oral administration of Echinococcus granulosus s.l. eggs. METHODS: E. granulosus s.s. eggs were obtained from the gravid segments of the adult worms collected from an experimentally infected dog. Thirty-four female Balb/c mice were allocated into 4 groups and were orally infected with E. granulosus s.s. eggs as follows: 1) the mice with normal immunity, a single dose of 1000 eggs, 2) the mice with normal immunity, 3 doses of 500 eggs, 3) immunosuppressed mice, a single dose of 1000 eggs, and 4) immunosuppressed mice, 3 doses of 500 eggs. After 6.5 months, all the mice were opened and their internal organs were examined for the presence of CE cysts. The livers of infected mice were also examined for the presence of E. granulosus s.l. compartments by the PCR method. RESULTS: There was no developed or developing CE cyst in the abdominal cavities or on the internal organs of all the mice in four groups. In addition, in the molecular study, all the examined liver samples were negative for the parasite material. CONCLUSION: The results of the present study revealed that Balb/c mice are not a suitable host for establishment of primary CE following the oral administration of E. granulosus s.s. eggs.