用免疫抑制小鼠快速培育抗苏拉明伊氏锥虫

RAPID DEVELOPMENT OF SURAMIN-RESISTANCE BY TRYPANOSOMA EVANSI IN IMMUNOSUPPRESSED MICE

将伊氏锥虫克隆ＪＧｍｃ５用环磷酰胺处理的免疫抑制小鼠频繁地连续传代，并予以亚治疗剂量的苏拉明治疗，连续传代１４次，历时８８日，即获得对苏拉明具有高水平抗药性的伊氏锥虫群体。在用免疫活性正常的健康小鼠测定抗药性时，此抗苏拉明锥虫群体仍保持高水平的抗药性，ＣＤ１００＞４００ｍｇ／ｋｇ。在以体外药敏试验测定时，其ＩＣ５０为１２３．２μｇ／ｍｌ。实验结果表明，宿主免疫系统的损害，在实验条件下，可导致伊氏锥虫迅速产生抗药性。在野外条件下，机体免疫系统的损害对锥虫抗药性的产生可能也起一定作用。

By mean of frequent passage in cyclophosphamide treated immunosuppressed mice given subcurative suramin treatment, a clone of Trypanosoma evansi rapidly developed high level of resistance to suramin after 14 passages over 88 days. The resistant population developed in immunomppressed mice maintained his high level of resistance (CD(100)>400 mg/kg) when tested in normal mice. IC(50) of it for suramin was 123.2μ/ml when tested by in vitro sensitivity test. The results indicate that impairment of the host immune system may lead to the rapid development of drug-resistance by T. evansi under experimental conditions in mice and mad possibly play a role in the development to drug-tesistance by trypanosomes in the field.