红霉素等四种抗生素体外抗弓形虫作用的研究

目的比较红霉素、阿奇霉素、磺胺嘧啶和大蒜素体外抗弓形虫的效果。方法用弓形虫RH株速殖子感染培养在盖玻片上的人包皮成纤维细胞(HFF),每一种药物设立2～3个浓度,分别在速殖子侵入细胞前和侵入细胞后作用于虫体,每隔1hr在倒置显微镜下观察细胞、弓形虫的形态及生长情况,3d后经吉氏染色,镜下观察,并将培养液注入小鼠腹腔,观察发病情况。结果红霉素的浓度在100μg/mL和150μg/mL时可抑制弓形虫的生长与繁殖,与剂量大小相关。阿奇霉素的浓度在20μg/mL时具有致虫体死亡的作用,>40μg/mL时对HFF有明显的毒性,其对弓形虫的作用效果与剂量大小相关。没有观察到100μg/mL、200μg/mL的磺胺嘧啶和20μg/mL、40μg/mL的大蒜素对弓形虫生长繁殖的抑制作用。结论红霉素在浓度大于100μg/mL时,可抑制弓形虫生长繁殖。阿奇霉素具有明显的杀灭速殖子的作用,但对细胞的毒性较大。磺胺嘧啶、大蒜素对弓形虫的生长抑制作用弱或无。

The in vitro effects of four antimicrobial agents on Toxoplasma gondii

To assess the in vitro effects of erythromycin, azithromycin, sulfadiazine and allicine on Toxoplasma gondii, the human foreskin fibrioblast (HFF) monolayer cultures on glass cover slip in dishes were infected with 3000 tachyzoites of T.gondii RH strain, and different concentrations of the antimicrobial agents were added to the cultures at the same time when the tachyzoites were added ,or after tachyzoites had invaded into the HFF cultures. The morphological changes and the growth conditions were observed under the inverted microscopy at one hour interval. After 3 days cultivation, the cover slips were taken out from dishes, washed with Hanks solution immediately, stained with Giemsa solution and examined under microscopy. The results showed that erythromycin could inhibit the growth and multiplication of T.gondii at concentrations of 100 150 μg/ml, but its effect was not parasiticidal. Azithromycin under concentration of 20μg/ml showed definite parasiticidal effect, but under concentration over 80 μg/ml it showed cytotoxic effect to the HFF cells.However,its inhibitory effect on T.gondii was closely correlated with the doses used. No inhibitory effect on the growth and multiplication of T.gondii was observed under concentrations of 100 and 200 μg/ml of sulfadiazine or 20 and 40 μg/ml of allicine.