旋毛虫不同地理株冷冻耐力的观察

Studies on the freezing resistance of different Trichinella isolates

目的观察旋毛虫不同地理株的冷冻耐力。方法将75只雄性昆明小鼠随机分为3组(每组25只),每组分别感染-18℃保存不同时间的旋毛虫河南株、云南株及乡土旋毛虫,每只小鼠经口接种300条肌幼虫。感染后42d剖杀,将全身骨骼肌消化后收集肌幼虫,测定其生殖力指数(Reproductive capacity index,RCI)。结果旋毛虫河南株-18℃保存0、6、12 h后的RCI分别为91.4、0.03及0(χ2=26.453,P<0.05),云南株-18℃保存0、6、12、24 h后的RCI分别为235.6、0.04、0.01及0(χ2=21.115,P<0.05);乡土旋毛虫-18℃保存0、6、12、24、48h后的RCI分别为34.6、26.8、21.9、10.8及7.4(F=8.505,P<0.05)。结论旋毛虫河南株与云南株对低温的抵抗力较低,-18℃分别保存12、24 h感染性已完全丧失;乡土旋毛虫对低温抵抗力较强,-18℃保存48 h仍有较强的感染性。

Objective To observe the freezing resistance of different Trichinella isolates. Methods Seventy- five male Kunming mice were randomly divided into 3 groups （25 mice per group）. Each group was infected with Henan and Yunnan isolates of Trichinella spiralis （T1） as well as T.nativa （T2） stored at -18℃ for different time,respectively. Each mouse was orally inoculated with 300 muscle larvae. All infected mice were slaughtered at 42 days post-infection. The muscle larvae were collected after all the skeletal muscles were digested,and reproductive capacity index （RCI） were determined. Results The RCI of Henan isolate of T. spiralis stored at -18℃ for 0,6,12 h was 91.4,0.03 and 0,respectively （X2= 26.453, P〈0.05 ）. The RCI of Yunnan isolate placed at -18℃ for 0,6,12,24 h was 235.6,0.04,0.01 and 0, respectively （X2= 21.115,P〈0.05）. The RCI of T.nativa freezed at -18℃ for 0,6,12,24,48 h was 34.6,26.8,21.9,10.8 and 7.4,respectively （F=8.505,P〈0.05）. Conclusions The resistance to freezing of Henan and Yunnan isolates of T. spiralis was lower,their infectivity has completely lost following storage at -18℃ for 12 and 24 h; resistance to freezing of T.nativa was higher,it remains infective after storing at -18℃ for 48 h.