低温对中国河南株旋毛虫肌幼虫生存能力和感染力的影响

摘要

目的：：了解低温(-18℃、-72℃)冻存对中国河南株旋毛虫肌幼虫(肌幼虫)生存能力和感染力的影响。方法：将含有肌幼虫的小鼠骨骼肌肌肉经-18℃、-72℃冻存处理不同时间后观察肌幼虫活力；55只小鼠分别经口感染300条经过-18℃、-72℃处理不同时间的肌幼虫，感染小鼠35 d后收集肌幼虫，测定生殖力指数( RCI)。结果：肌幼虫经-18℃冻存0、6、12、24、36、48 h的死亡率分别为0.00%、6.30%、18.23%、35.81%、74.60%及100.00%；经-72℃冻存0、15、30、45、60 min的死亡率分别为0.00%、21.21%、57.11%、86.24%及100.00%；肌幼虫死亡率随-18℃、-72℃冻存处理时间的延长而升高(P<0.01)。经过-18℃冻存处理6、12、24、36 h后感染小鼠的肌幼虫RCI分别为(126.38±6.90)、(68.58±4.83)、(12.58±1.77)、(5.77±0.77)，与未冻存(0 h)组肌幼虫的 RCI(163.70±10.70)差异均有统计学意义(P <0.01)；通过-72℃冻存处理15、30、45 min后感染小鼠的RCI分别为(18.19±2.15)、(8.83±1.39)、(3.10±0.26)，与未冻存(0 min)组肌幼虫的RCI(163.70±10.70)差异均有统计学意义(P<0.01)；肌幼虫的RCI均随-18℃、-72℃冻存处理时间延长而下降(P<0.01)。结论：低温冻存可导致中国河南株肌幼虫存活能力和感染能力下降，-18℃冻存48 h或-72℃冻存60 min可完全灭活小鼠肌肉内的中国河南株肌幼虫。%Objective:To investigate the influence of the low temperture ( -18 ℃ and -72 ℃) on the viability and infectivity of Trichinella spiralis muscle larvae. Methods:The viability of the Trichinella spiralis muscle larvae in mice skeletal muscle were observed after -18 and -72 ℃ of freezing. Fifty-five mice were infected with 300 muscle larvaes treated with low temperature ( -18 and-72 ℃) by oral. The muscle larvae in mice was collected after 35 d of infection,the reproductive capacity index( RCI) of which was determined. Results:The death rate of the muscle larvae stored at the -18 ℃ for 0 h,6 h,12 h,24 h,36 h and 48 h were 0. 00%, 6. 30%,18. 23%,35. 81%,74. 60% and 100. 00%. The death rate of the muscle larvae stored at the -72 ℃ for 0 min,15 min, 45 min and 60 min were 0. 00%,21. 21%,57. 11%,86. 24% and 100. 00%,respectively. The death rate of the muscle larva stored at-18 ℃ and -72 ℃ increased with the prolonging of the storing time(P<0. 01). The RCI of the muscle larvae stored at -18 ℃ for 0 h,6 h,12 h,24 h and 36 h were(163. 70 ± 10. 70),(126. 38 ± 6. 90),(68. 58 ± 4. 83),(12. 58 ± 1. 77) and(5. 77 ± 0. 77), respectively,and the difference of which was statistically significant(P<0. 01). The RCI of the muscle larva stored at -72 ℃ for 0 min,15 min,30 min,45 min,were(163. 70 ± 10. 70),(18. 19 ± 2. 15),(8. 83 ± 1. 39) and(3. 10 ± 0. 26),respectively,and the difference of which was statistically significant(P<0. 01). The RCI of the muscle larva stored at the -18 ℃ or -72 ℃ decreased with the prolonging of the storing time(P<0. 01). Conclusions:Cryopreservation can lead to the decreasing of viability and infectivity of Trichinella spiralis muscle larvae in Henan. The muscle larvae stored at the 18 ℃ for 48h or -72 ℃ for 60 min can be completely inactivated.