旋毛虫各隔离种对猪的感染性和低温耐受性的研究

Infectivity and Freeze Resistance of Trichinella Isolates in Pigs and Mice in Heilongjiang Province, China

用消化法所得的猪旋毛虫、犬旋毛虫、旋毛形线虫（Trichinella spiralis）和本地毛形线虫（Trichinella nati-va）分别感染猪和小鼠,以观察其感染性,同时在-22℃和-32℃条件下对其进行冷冻试验。结果表明:4个旋毛虫隔离种对猪的感染性存在着明显差异,猪旋毛虫和T.spiralis对猪易感,其繁殖力指数（RCI）分别为385.68±41.51和300.55±12.45;而犬旋毛虫和T.nativa对猪不易感,RCI分别是0.064±0.031和0.033±0.033。猪旋毛虫和旋毛形线虫不耐低温,在猪体内-32℃、24 h,-22℃、72 h;在小鼠体内-32℃、12 h即全部死亡。而犬旋毛虫和本地毛形线虫对低温抵抗力较强,在猪体内-32℃、72h,-22℃、192 h;在小鼠体内-32℃、48 h才失去感染性。结果揭示:黑龙江省猪旋毛虫相当于旋毛形线虫,犬旋毛虫相当于本地毛形线虫;犬旋毛虫和T.nativa很难通过猪的感染而对人体健康构成威胁。

Infectivity and freeze resistance of Trichinella from swine and dog, and the international standard isolates: Trichinella spiralis and Trichinella nativa in pigs and mice were compared in Heilongjiang province,China. It was found that infectivity of swine isolate ,dog isolate , T. spiralis and T. nativa in pigs was significantly different. Swine isolate and T. spiralis were highly infective to pigs with Reproductive Capacity Indexes(RCI) of 385.68 and 300.55 respectively, however, pigs were relatively refractor to dog isolate and T. nativa with RCIs of 0.064 and 0.033 respectively. Dog isolate and T. nativa were more resistant to freeze than swine isolate and T. spiralis in pig and mouse muscle. Swine isolate and T. spiralis would become uninfective after 72 hours at - 22℃ and 24 hours at - 32℃ in pigs ,and 12 hours at - 32℃ in mice,but dog isolate and T. nativa could survive after 192 hours at - 22℃ and 72 hours at - 32℃ in pigs, and 48 hours at - 32℃ in mice. It is concluded that Trichinella from swine and dog in Heilongjiang province, China belong to Trichinella spiralis and Trichinella nativa respectively, Trichinella from dog is not infective to pigs,and would not present a major zoonotic threat to the human consumer via pigs inadvertently becoming infected.