A new technique to avoid losing the strains of Echinococcus multilocularis during passaging

OBJECTIVE: To examine the survival of Echinococcus multilocularis (E. multilocularis) and the formation of protoscoleces, under refrigerated conditions over a 43-day observation period.

METHODS: We conducted this study in Ege University, School of Medicine, from May-December, 2004. We included 4 healthy females and 2 males, 8-12 week old M. unguiculatus species (approximately 60-70 gr) for the study, as they are known to be susceptible to E. multilocularis. In this experimental study, we aimed to define a technique to keep the strains during these passages.

RESULTS: We found preserved viability and virulence of E. multilocularis stored in RPMI 1640 plus 10% fetal calf serum at +40C. We accomplished the infection of the Meriones unguiculatus after in-vivo passaging from that flask, which we kept at +40C, and this proves the viability of protoscoleces and membranous structures perfectly at the 43rd day.

CONCLUSION: We also found that E. multilocularis metacestodes and the formation of protoscoleces keep their viability up to 60 days and virulence up to 43 days under this condition. We recommend storing an extra flask during each passage as a precaution against losing strains.