Clark C G, Diamond L S
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Exp Parasitol. 1993 Dec;77(4):450-5. doi: 10.1006/expr.1993.1105.
The ability to identify individual isolates of Entamoeba histolytica Schaudinn 1903 (Emend. Walker 1911) is necessary before several important epidemiological questions can be answered. We have developed such a method based on our discovery of extensive polymorphism in two E. histolytica genes--the serine-rich antigen gene and the "strain specific gene"--each of which has an internal tandemly repeated structure. Using the polymerase chain reaction we detected both size and restriction site polymorphisms in the repetitive regions. When the two genes were used in combination we obtained 16 distinct DNA patterns out of 18 isolates examined. Moreover, these patterns proved to be stable under a variety of conditions--long-term culture, axenization, cell cloning, and animal passage.
在回答几个重要的流行病学问题之前，有必要具备鉴定1903年（经沃克1911年修订）溶组织内阿米巴各个分离株的能力。我们基于在溶组织内阿米巴的两个基因——富含丝氨酸抗原基因和“菌株特异性基因”中发现的广泛多态性，开发了这样一种方法，这两个基因均具有内部串联重复结构。利用聚合酶链反应，我们检测到了重复区域的大小和限制性酶切位点多态性。当将这两个基因结合使用时，在检测的18个分离株中获得了16种不同的DNA模式。此外，这些模式在多种条件下——长期培养、无菌培养、细胞克隆和动物传代——都被证明是稳定的。
