我国山丘疫区与平原疫区利什曼原虫分离株分子核型分析

ANALYSIS OF MOLECULAR KARYOTYPE OF LEISHMANIA ISOLATES FROM HILLY FOCI AND PLAIN FOCI OF CHINA

目的：分析我国山丘疫区和平原疫区利什曼原虫分离株分子核型。方法：脉冲场电泳。采用１％琼脂糖凝胶，电压６Ｖ／ｃｍ，０．５×ＴＢＥ，１４℃，脉冲时间６０ｓ，电泳１５ｈ和脉冲时间９０ｓ，电泳９ｈ。结果：各个分离株均分离出分子量范围在２００ｋｂ－２２００ｋｂ的ＥＢ染色条带为１５条左右，其中６个山丘疫区分离株之间的核型相似，且犬株与人株的亦相似，并与Ｌ．ｉｎｆａｎｔｕｍ的核型接近；２个平原疫区分离株之间的核型相似；山丘疫区与平原疫区分离株之间的核型不同。结论：山丘疫区分离株之间和平原疫区分离株之间均各自存在着同源性，山丘疫区分离株与Ｌ．ｉｎｆａｎｔｕｍ之间存有部分同源性，但两个疫区分离株之间存在着异源性；保虫宿主——家犬，是我国山丘疫区内脏利什曼病的重要传染源。

AIM: To analyse the molecular karyotypes of Leishmania isolates from hilly and plain foci of China. METHODS: Pulsed field gel electrophoresis(PFGE) was performed in 1% agarose at 6 V/cm in 0.5×TBE at 14℃ with a pulse time of 60 s for 15 h and a pulse time 90 s for 9 h. RESULTS: Each isolate was resolved into 15 different EtBr staining bands ranging in size from 200 to 2 200 kb, in which the karyotypes of 6 isolates from hilly foci were similar(including karyoptypes of canine isolates similar with those of human isolates),and they were partly similar with those of L.infantum . The karyotypes of the two isolates from plain foci were similar, but the isolates from the two topographically different foci were different from each other. CONCLUSION: Homology exists between L.d. isolates from hilly foci and plain foci respectively, and exists in part between L.d. isolates from hilly foci and L.infantum; while heterogeneity exists between L.d .isolates from hilly foci and plain foci. The reservoir host, domestic dog, plays an important role as the infection source of leishmaniasis in the hilly foci of China.