Comparison on the Developments of Metacestodes of Echinococcus multilocularis and Echinococcus sibiricensis in the Experimentally Infected Meriones unguiculatus

Histogenesis in the metacestode of Echinococcus multilocularis and Echinococcus sibiricensis were observed in laboratory Meriones unguiculatus inoculated intraperitoneally with finely minced infective vesicles respectively from experimental KM strain white mice which were infected with the adults of the both species echinococcus collected from Vulpes corsac in Hulun Buir Pasture of Inner Mongolia, China. The fragments of alveolar Echinococcus multilocularis and alveolar Echinococcus sibiricensis developed in the livers and peritoneal cavities of mongolian Meriones unguiculatus. Their mature alveolar hydatids and alveolar tumours were obtained in 4~14 months and 7.3~9.5 months after infections respectively. The results of experimental infections in laboratory mongolian gerbils with alveolar Echinococcus multilocularis and alveolar Echinococcus sibiricensis campared to the metacestodes of the both species in experimentally infected white mice, they were very similar to each other respectively. According to the results of comparison observation on the developments of the metacestode of Echinococcus sibiricensis and Echinococcus multilocularis in experimental white mice and experimental mongolian gerbils, it is clear, there are different embryological developments in the two species of Echinococcus. In metacestode of E. sibiricensis, its protoscoleces and brood capsules are formed from the proliferation, metastasis and development of free germinal tissue masses, while in metacestode of E. multilocularis, its brood capsules and protoscoleces are formed from the proliferation, budding and development of the germinal cells and substance layer attaching on inner surface of cyst wall. Thus authors thought that the Echinococcus sibiricensis (Rausch and Schiller, 1954) be not a geographically strain or subspecies of european Echinococcus multilocularis (Leuckart, 1863), however, must be a separative species of Echinococcus.