SD大鼠肠道菌群多样性对金黄色葡萄球菌检出率影响的探析

Effects of intestinal flora diversity on the detection rate of staphylococcus aureus in SD rats

目的 探讨SD大鼠肠道菌群多样性对金黄色葡萄球菌(Staphylococcus aureus,SA)检出率的影响。方法 无特定病原体(SPF级)初断乳SD大鼠和成年SD大鼠各30只,采集其回盲部肠道内容物,进行SA分离鉴定和肠道菌群16 s区域扩增子测序,使用Qiime和R软件进行多样性及丰度分析,找出组间差异,分析肠道菌群多样性对SA检出率的影响,以P<0.05为差异有统计学意义。结果 SA检出率初断乳SD大鼠为16.7%,成年SD大鼠为3.3%;肠道菌群中最大丰度物种一致,但初断乳SD大鼠肠道菌群可操作分类单元(Operational taxonomic units,OTUs)有1 231个,成年SD大鼠1 415个;初断乳SD大鼠的肠道菌落组成结构差异比成年SD大鼠更大,物种多样性指数小于成年SD大鼠,差异有统计学意义(P<0.05),在门水平疣微菌门、脱铁杆菌门、生氧光细菌初断乳SD大鼠丰度大于成年SD大鼠(q均小于0.05),软壁菌门初断乳SD大鼠丰度低于成年SD大鼠(q<0.05)。初断乳SD大鼠中检出SA大鼠分出697个OTUs,未检出SA大鼠分出934个OTUs;检出SA大鼠肠道菌群物种多样性指数小于未检出SA大鼠,有统计学意义(P<0.05),厚壁菌门丰度大于未检出大鼠,变形菌门丰度低于未检出大鼠(q<0.05)。结论 大鼠肠道菌群多样性与SA检出率有一定联系,肠道菌群越丰富,菌群结构越稳定SA检出率越低。

Objective To investigate the effects of intestinal flora diversity on the detection rate of Staphylococcus aureus(SA) in SD rats. Methods There were 30 newly weaned SD rats and 30adult SD rats(SPF),we got intestinal contents of the ileocecal part to separate SA and sequencing the 16 s region of the intestinal flora. Qiime and R software were used to analyze the diversity and abundance and indentify with differences between groups. The influence of intestinal flora diversity on SA detection rate was analyzed, and the differences P<0.05 was considered to be statistically significant. Results The detection rate of SA was 16.7% in weaned rats and 3.3% in adult rats. The maximum abundance of the species in the instestinal flora was consistent. There were 1 231 OTUs in the weaned rats and 1 415 in the adult rats. The difference of composition and structure of intestinal colonies of weaned SD rats was greater than that of adult SD rats. The species diversity index of weaned rats was lower than that of adult SD rats,the difference was statistically significant(P<0.05). The relative abundance of Verrucomicrobia,Deferribacteres and Oxyphotobacteria in the weaned SD rats were greater than that of adult rats(q<0.05), and the relative abundance of Tenericutes in weaned SD rats was lower than that of adult rats(q<0.05). In the weaned rats,there were 697 OTUs were detected in SA rats and 934 OTUs were detected in non-SA rats.The species diversity index of intestinal flora in detected SA rats were low than that of non-SA rats,the difference was statistically significant(P<0.05). The relative abundance of Firmicute in detected SA rats were greater than that of undetected rats and the relative abundance of Proteobacteria was lower than that of undetected rats(q<0.05). Conclusions The diversity of intestinal flora in rats is associated with the detection rate of SA, the richer and the more stable the bacterial flora result in the lower detection rate of SA.