Influence of Lysostaphin on intestinal microbiota in mice | 溶葡萄球菌素对小鼠肠道菌群结构的影响

Chinese. 研究溶葡萄球菌素对小鼠肠道菌群结构的影响，为溶葡萄球菌素的食用安全性评估提供参考。将24只7周龄ICR小鼠随机分为3个试验组和对照组，3个试验组分别提供溶葡萄球菌素含量为1 μg/mL（低剂量）、5 μg/mL（中剂量）和15 μg/mL（高剂量）的饮水10 mL/(只•d)，于饮用第0(饮用前)，1，3，7，14，21天以及停饮第3，7，14天采集小鼠新鲜粪便样品，采用PCR-DGGE技术检测小鼠肠道菌群结构变化。DGGE图谱显示，各组小鼠试验前后不同时间肠道内的优势菌种相似；经UPGMA聚类分析，与对照组相比，低、中剂量溶葡萄球菌素对小鼠肠道菌群结构影响较小，高剂量溶葡萄球菌素对小鼠肠道菌群结构影响较大；差异性分析结果显示，试验组饮用各阶段带谱与试验前的相似性与对照组相应阶段的相似性差异均不显著（P＞0.05），溶葡萄球菌素低、中和高剂量组在停饮后第7天带谱与饮用前的相似性分别达到了70.8%，66.9%和63.8%；对图谱中主要条带进行测序和比对分析，结果表明，高剂量溶葡萄球菌素对小鼠肠道中Lactobacillus taiwanensis和1株不可培养细菌有促进作用。溶葡萄球菌素对小鼠肠道菌群结构的改变具有浓度依赖性，且停饮后小鼠肠道菌群结构有一定程度的恢复。

English. The aim of the present study was to investigate the effect of lysostaphin on intestinal microbiota in mice to give reference for food safety assessment of the Lysostaphin. Twenty four 7-week-old mice were randomly assigned into three experimental groups and control group, experimental groups mice were fed 1 μg/mL(low-dose group), 5 μg/mL(medium-dose group) and 15 μg/mL(high-dose group) doses of lysostaphin respectively, 10 mL for each mouse per day, samples were collected on 0，1，3 ，7 ，14 and 21 d, 3，7 and 14 d after taking stopped for detecting of the intestinal microbiota structural changes by PCR-DGGE. DGGE profiles showed that the dominant bacteria of each group in different time points were present in the intestinal gut; UPGMA clustering analysis displayed that the low-dose and medium-dose group had little effect, and the high-dose group had a greater impact in the microflora of mice compared with the control group; The results of difference analysis showed that the similarity between the bands of each group before and after the test was not significant compared with corresponding stage of the control group(P＞0.05), and the similarities were 70.8%, 66.9% and 63.8% of each group from low to high respectively on the 7th day after taking stopped compared with before; Sequencing analysis of the major bands in the profiles showed that lysostaphin in 15 μg/mL dose promoted the culture of Lactobacillus taiwanensis. Changes in the structure of intestinal flora in mice were induced by lysostaphin in a dose-dependent way, and with the extension of stop-feeding time, the mouse intestinal microflora had a certain degree of recovery.