中文摘要：

【目的】通过小鼠的急性毒性、30d喂养及细菌移位试验，对马奶及其制品（酸马奶）中分离出来的7株肠球菌属乳酸菌进行初步安全性评价。【方法】分别对小鼠连续7d及30d灌胃不同剂量的肠球菌JHZ9、JHZ15、JHZ17、JHZ22、JHZ25、JHZ28、JNN1，对其一般体征进行观察，记录体重和食物摄入量，最后进行大体解剖，观察肝、肾、脾、心、肺并称重，同时进行细菌移位试验。【结果】除30d喂养中，试验菌株JHZ17的高剂量组与生理盐水组差异显著（P〈0．05），7d急性毒性试验及30d喂养试验中各试验组小鼠体重、食物摄入量与对照组相比无显著性差异（P〉0．05），30d喂养后小鼠各脏器（心、肝、脾、肺、肾）指标与对照组无显著性差异（P〉0．05），小鼠的经口急性毒性最大耐受剂量（MTD）大于10^10 CFU／（mL bw）20mL／（kg·d），属无毒级别，未发现细菌移位现象。【结论】肠球菌JHz9、JHZ15、JHZ17、JHZ22、JHZ25、JHZ28、JNN1安全，无毒副作用。

英文摘要：

[Objective] The safety assessment of 7 strains of lactic acid bacteria （Enterococcus spp.） isolated from mare＇s milk and its products （koumiss） was investigated in a mice feeding trial. Acute toxicity, thirty days feeding and bacterial translocation were conducted. [Methods] Different dose of Enterococcus JHZ9, JHZ15, JHZ17, JHZ22, JHZ25, JHZ28 and JNN1 were administrated to treatment groups separately by gavage for 7 days and 30 days, while the general appearances, body weight and food consumption were observed and recorded daily. Mice were killed after 30 days and the kidney, spleen, liver, heart and lungswere observed and weighted, then collected for bacterial translocation experiment. [Results] Except that test bacterial strains JHZ17 in the high dose grouphad significant difference with control group （P〈0.05）. experiments, no significant differences （P〉0.05） were In both acute toxicity and thirty days feeding found between the treatment group and the control group in the weight of mice, food intake and the internal organ （heart, liver, spleen, lung and kidney） indices. The maximum tolerated dose （MTD） of acute toxicity is higher than 10^10 CFU/（mL bw） 20 mL/（kg.d）, within the range of non-toxic. No bacterial translocation was observed. [Conclusion] Lactic acid bacteria JHZ9, HZ15, JHZ17, JHZ22, JHZ25, JHZ28 and JNN1 have no toxicity and side effects.