Studies on Biological Characteristics of Trichinella Isolates

Biological characteristics of Trichinella from swine and dog in Heilongjiang province, China were first investigated in combination with studies in biology, the international standard Trichinella isolates, T. spiralis and T. nativa were used as the control. The results indicated as follows:1. Development time of nurse cells around muscle larvae in mice diaphragms was different, at 16 days postinfection (d.p.i.) for swine isolate, at 18,20 and 22d.p.i.for T. spiralis, dog isolate and T. nativa. The 100% level of encapsulation occurred at 32 d.p.i. for dog isolate and T. nativa, at 36 d.p.i. for T. spiralis and at 38 d.p.i. for swine isolate.2.Adult worm longevity of swine isolate, T. spiralis, dog isolate and T. nativa was 22, 20, 16 and 14 days during the intestinal phase respectively; 3. Intestinal distribution of Trichinella from swine and dog, T. spiralis and T. nativa was mainly anterior and middle position in mice, but the number of dog isolate and T. nativa were higher than swine isolate and T.spiralis (P0.01).On the basis of the results, it is concluded that Trichinella from swine and dog in Heilongjiang province China belong to Trichinella spiralis and Trichinella nativa, respectively.