Molecular epidemiology of Entamoeba spp.:: Evidence of a bottleneck (Demographic sweep) and transcontinental spread of diploid parasites
Molecular epidemiology of Entamoeba spp.:: Evidence of a bottleneck (Demographic sweep) and transcontinental spread of diploid parasites
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DOI：
10.1128/jcm.38.10.3815-3821.2000
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发表时间：
2000-10-01
影响因子：
9.4
通讯作者：
Samuelson, J
中科院分区：
文献类型：
--
作者：
Ghosh, S;Frisardi, M;Samuelson, J
在墨西哥和印度等发展中国家，溶组织内阿米巴引起阿米巴性结肠炎和肝脓肿。异内阿米巴在形态上是相同的，但与疾病无关。在这里，我们确定了溶组织芽孢杆菌的倍性，并开发了基于pcr的方法来区分野区分离株。溶组织菌或溶组织菌。荧光原位杂交显示，5个“单拷贝”探针的溶组织芽孢杆菌滋养体为二倍体。新、旧大陆临床分离的溶组织芽胞杆菌超氧化物歧化酶和肌动蛋白3基因的基因间序列完全相同。dispar。这些结果表明，在感染人类的内阿米巴虫中出现了瓶颈或人口普查。而在滋养体（富丝氨酸蛋白）和寄生体（几丁质酶）表面编码重复抗原的溶组织芽孢杆菌和异异芽孢杆菌基因则高度多态性。几次质酶等位基因表明，墨西哥墨西哥城的HM-1和印度加尔各答的NIH-200溶组织芽胞杆菌的早期灭活菌株仍然存在，并且在新旧世界都可以发现类似的异芽胞杆菌寄生虫。富丝氨酸蛋白等位基因表明墨西哥城存在HM-1菌株，包括一些预测富丝氨酸蛋白重复次数很少的溶组织芽胞杆菌基因。这些结果表明，几丁质酶和富含Ser-r蛋白位点的多样化选择，证明了这些等位基因对区分溶组织芽孢杆菌和异芽孢杆菌的临床分离株的有用性。
Entamoeba histolytica causes amebic colitis and liver abscess in developing countries such as Mexico and India. Entamoeba dispar is morphologically identical but is not associated with disease. Here we determined the ploidy of E. histolytica and developed PCR-based methods for distinguishing field isolates off. histolytica or E. dispar. Fluorescence in situ hybridization showed that E. histolytica trophozoites are diploid for five "single- copy" probes tested. Intergenic sequences between superoxide dismutase and actin 3 genes of clinical isolates of E. histolytica from the New and Old Worlds were identical, as were those off. dispar. These results suggest a bottleneck or demographic sweep in entamoebae which infect humans. In contrast, E. histolytica and E. dispar genes encoding repeat antigens on the surface of trophozoites (Ser-rich protein) or encysting parasites (chitinase) were highly polymorphic. chitinase alleles suggested that the early axenized strains of E. histolytica, HM-1 from Mexico City, Mexico, and NIH-200 from Calcutta, India, are still present and that similar E. dispar parasites can be identified in both the New and Old Worlds. Ser-rich protein alleles, which suggested the presence of the HM-1 strain in Mexico City, included some E. histolytica genes that predicted Ser-rich proteins with very few repeats. These results, which suggest diversifying selection at chitinase and Ser-r ich protein loci, demonstrate the usefulness of these alleles for distinguishing clinical isolates of E. histolytica and E. dispar.