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目的对广西龙州果子狸旋毛虫分离株进行虫种研究,确定当地是否存在新虫种。方法对龙州果子狸旋毛虫分离株进行囊包形态学、毒力和保姆细胞形成时间进行实验观察。提取并且扩增该旋毛虫及从德保、南丹野鼠体内分离的旋毛虫、河南旋毛虫分离株细胞色素氧化酶1(COX1)基因,分析同源性及遗传距离,构建系统发生树,并且与Genbank已知的旋毛虫相应基因序列进行对照比较。结果龙州旋毛虫分离株原代囊包的平均大小为328.72μm×236.42μm。小鼠接种旋毛虫(2 000条/只)后,半数死亡天数为24～25d,死亡率为84.62%。小鼠感染后第18d开始形成保姆细胞,第34d后保持在较高水平波动,至56d实验结束时仍可见少量游离幼虫,未见钙化死亡囊。龙州旋毛虫分离株和南丹旋毛虫分离株、河南分离株之间COX1的同源性为99.8%～100.0%,遗传距离为0.000～0.003。龙州旋毛虫分离株、南丹旋毛虫分离株及河南分离株与基因库中T.spiralis COX1基因的同源性为98.8%～99.0%,遗传距离为0.003～0.005。构建的系统发生树显示,果子狸分离株与德保、南丹分离株及Genbank中的T.spiralis在同一分枝,与其它旋毛虫种在不同的分枝。结论广西龙州发现果子狸自然感染旋毛虫,与广西德保、南丹两县野鼠体内分离旋毛虫为同一虫种,即T.spirilas,广西未发现新的旋毛虫种株。
Objective To study the species of Trichinella spiralis isolates from Longzhou, Guangxi to determine whether new species exist in the area. Methods The morphology, virulence and nanosized cells formation of Trichinella spiralis isolates from Longzhou were observed experimentally. The Trichinella spiralis and Trichinella isolates from Trichosanthes and Nandanus were extracted and amplified, and the cytochrome oxidase 1 (COX1) gene of Trichinella spiralis was isolated and analyzed for homology and genetic distance to construct phylogenetic tree. And GenBank known trichine corresponding gene sequence comparison. Results The average size of primary sarcolemma of Trichinella spiralis isolates was 328.72μm × 236.42μm. After the mice were inoculated with Trichinella spiralis (2000), half the number of deaths was 24-25 days and the mortality rate was 84.62%. At the 18th day after infection, the nurse cells began to form, and kept high level after 34 days. A small amount of free larvae could still be seen at the end of 56 days experiment. No calcified cysts were found. The homology of COX1 between Trichinella spiralis and Nantan Trichinella isolates and Henan isolates was 99.8% ~ 100.0% and the genetic distance was 0.000 ~ 0.003. The homology of T.spiralis COX1 gene in Trichinella isolates from Longzhou, Nantan Trichinella isolates, and Henan isolates was from 98.8% to 99.0% with genetic distance from 0.003 to 0.005. The phylogenetic tree constructed showed that the civet cats were on the same branch as T.spiralis in Duroc, Nandan isolates and Genbank, and had different branches with other Trichinella species. Conclusions Natural civet cats were found to be infected with Trichinella spiralis in Longzhou, Guangxi Province. The same species was isolated from Trichinella spiralis in Tiefu and Nandan counties in Guangxi Province, namely T.spirilas. No new Trichinella strains were found in Guangxi.