用限制性内切酶分析溶组织内阿米巴的致病性

用SH-3、SH-5、SH-6、SH-7和SH-85株溶组织内阿米巴的DNA增殖35个周期,将其基因DNA用内切酶HinfⅠ和EcoT22Ⅰ进行消化后,作琼脂糖凝胶电泳分析,显示,5株虫株DNA经35个循环周期后产生531-bp的产物;经HinfⅠ消化后,SH-3、SH-5、SH-6和SH-7的基因DNA产生3个相同的片段,而显示其均与非致病性虫株SAW142的电泳谐完全相同;而SH-8基因DNA的电泳谱与致病性虫株SAW408的电泳谱一致,而用EcoT22Ⅰ消化结果也显示SH-8的图谱与致病性虫株SAW408的相同,证实了从包囊携带者和有发热、腹泻而无脓血便患者粪便中分离的虫株均属于非致病性虫株,从有发热、腹泻、脓血便的急性阿米巴痢疾患者粪便中分离到的虫株属于致病性虫株,均与酶株群分析相一致。提示,应用多聚酶链反应和限制性内切酶消化基因DNA来检测溶组织内阿米巴的基因型是十分有意义的。

PATHOGENICITY ANALYSIS OF ENTAMOEBA HISTOLYTICA AFTER RESTRICTION-ENDONUCLEASE TREATMENT

DNA from five strains of Entamoeba histolytica, SH-3, SH-5, SH-6, SH-7 and SH-8 were amplified 85 cycles by the polymerase chain reaction (FOB) followed by digestion by restriction-endonuclease Hinfl and EcoT22I resulted in -581-bp products. Hinfl digestion of SH-3, SH-5, SH-6 and SH-7 FOR products consistently yielded the same three fragments. The digestion pattern obtained was identical to that of the nonpathogenic SAW 142 control strain. The digestion pattern of SH-8 FOR products was identical to that of the pathogenic' SAW 408 strain, and it DNA was similarly split into 2 fragments by EcoT22I. These observations indicate that 4 strains of E. Bistolytica isolated from cyst carriers and patients with fever and diarrhea but without purulent discharge are genotypically nonpathogenic, whereas SH-8 derived from patient with fever, diarrhea and purulent bloody-stool is genotypically pathogenic. These results completely correlate with zymodeme analysis. The genotypical identification of E. Histolytica using FOR and restriction-endonuclease digestion of amplified genomic DNA is Tery valuable.