【摘要】 应用RT-PCR方法对南京、上海和合肥猪源隐孢子虫卵囊SSU rRNA部分序列进行扩增,产物测序后提交GenBank,收录号为DQ855266、DQ855267;用BLAST和DNAStar软件与GenBank参考序列进行比较,分析其同源性,绘制系统发育进化树,结合卵囊形态学观察和对小鼠、大鼠、兔、山羊和鸡的传染性试验确定隐孢子虫种类或基因型。结果表明,3地区猪源隐孢子虫分离株与微小隐孢子虫(C.parvum)同源性达94%~100%,与C.parvum"mouse"型有99.8%~100%的同源性,并处于进化树的同一分支。因此,3地区猪源隐孢子虫是C.parvum"mouse"型,提示猪和鼠之间存在交叉传播的可能。更多还原

【Abstract】 To investigate the genotypes of Cryptosporidium parasiting in pigs in Nanjing,Shanghai and Hefei,the total RNA of the oocysts from 6 positive feces was extracted using the TRIZOL reagent,and the partial genes of the small subunit ribosomal RNA(SSU rRNA) were amplified by the reverse transcription polymerase chain reaction(RT-PCR).SSU rRNA gene fragments of the isolates were deposited in the GenBank database under accession NO.DQ855266,DQ855267 and compared with sequences of various Cryptosporidium spp.and genotypes on the NCBI server using the BLAST and DNAStar software by the analysis of the homologous rate and phylogenetic tree.The results showed that the SSU rRNA gene fragments,compared with sequences of various Cryptosporidium spp.and genotypes,belonged to the species C.parvum with 94%-100 % homologous rate,and were most similar to the C.parvum "mouse" genotype with 99.8%-100 % homologous rate.The phylogenetic tree and sequence distances generated showed that those isolates belong to the C.parvum groups,and lie in the same divarication with C.parvum "mouse" genotype.It is concluded that those isolates are clearly distinct from other sequences as to merit species status,which is C.parvum "mouse" genotype from pigs.There might be a cross-transmission between pigs and mice.更多还原