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首页> 外文期刊>Infection and immunity >Changes in isoenzyme patterns of a cloned culture of nonpathogenic Entamoeba histolytica during axenization.
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Changes in isoenzyme patterns of a cloned culture of nonpathogenic Entamoeba histolytica during axenization.

机译：非致病性溶组织变形杆菌的克隆培养过程中同工酶模式的变化。

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The axenization of an Entamoeba histolytica isolate with a nonpathogenic isoenzyme electrophoretic pattern (zymodeme) was recently achieved for the first time (15). Forty days after the cells were transferred to the medium used for axenic cultivation, the amebae developed virulence properties, and the zymodeme converted to a pathogenic pattern. To exclude the possibility that the original isolate consisted of two zymodeme populations and that conditions of growth selected for a particular population, the experiment was repeated with a cloned culture of a nonpathogenic (zymodeme III) strain, E. histolytica SAW 1734R clAR, isolated by and obtained from P. G. Sargeaunt. Axenization was accomplished, as before, by transferring trophozoites to TYI-S-33 medium containing a mixture of antibiotics to suppress the growth of the associated bacterial flora and a nutritional supplement consisting of gamma-irradiated bacteria. A change in the hexokinase and phosphoglucomutase isoenzyme pattern was observed 21 days after the amebae had been transferred to the axenic medium but before complete axenization of the amebae had occurred. The change in zymodeme was accompanied by an increase in virulence, as evidenced by the ability of fewer amebae to induce hepatic abscesses in hamsters. A reverse conversion to a nonpathogenic zymodeme was also accomplished by reassociating and subculturing the newly converted pathogenic trophozoites of strain SAW 1734R clAR with the bacterial flora that accompanied this ameba in the original xenic culture. The electromobilities of the hexokinase isoenzymes changed back to their original pattern 7 days after the amebae were returned to xenic growth conditions. Our in vitro results demonstrate that culture conditions and bacterial flora can cause changes in the zymodeme and virulence of a cloned ameba isolate and raise the concern that this could happen also in vivo. Thus, the finding of a particular zymodeme in a culture of E. histolytica isolated from a carrier should not be used to predict a clinical condition or serve as a basis for the recommendation of therapy.
机译：最近首次实现了具有非致病性同功酶电泳图谱（zymodeme）的溶组织变形杆菌的分离。在将细胞转移到用于无菌培养的培养基中四十天后，变形虫表现出了毒力特性，并且酶模式转化为致病模式。为了排除最初的分离株包含两个酶切菌群以及为特定菌群选择生长条件的可能性，对非致病性（zymodeme III）菌株E. histolytica SAW 1734R clAR的克隆培养进行了重复实验，并从PG Sargeaunt获得。如前所述，通过将滋养体转移到含有抗生素混合物以抑制相关细菌菌群生长的TYI-S-33培养基和由伽马射线辐照的细菌组成的营养补品中，从而实现了轴突化。在变形虫被转移到轴心性培养基中21天后，但在完全变形的变形虫之前，己糖激酶和磷酸葡萄糖突变酶同工酶模式发生了变化。 zymodeme的变化伴随着毒力的增加，这表现为更少的变形虫诱导仓鼠肝脓肿的能力。还可以通过将新转化的SAW 1734R clAR菌株的致病滋养体与伴随该变形虫的细菌菌群重新结合并传代培养，使其转化为非致病菌。在变形虫回到异种生长条件后7天，己糖激酶同工酶的电迁移率又恢复到其原始模式。我们的体外结果表明，培养条件和细菌菌群会导致克隆的变形杆菌分离株的酶模式和毒力发生变化，并引起人们担心这种情况也可能在体内发生。因此，在从载体中分离出的溶组织性大肠杆菌的培养物中发现特定的酶，不应被用于预测临床状况或作为推荐治疗的基础。

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