【摘要】：目的：了解兒童腸道菌群的組成和使用β-內(nèi)酰胺類抗生素后腸道細菌組成的影響。 方法：1.標(biāo)本采集：分別采集3-5歲健康且一月內(nèi)無抗生素使用史兒童糞便樣本10例(對照組)及同年齡組一周內(nèi)有β-內(nèi)酰胺類抗生素使用史的兒童糞便樣本4例(抗生素組)。2.提取糞便DNA并進行16S rRNA基因擴增；將擴增產(chǎn)物與擴增質(zhì)粒連接后轉(zhuǎn)導(dǎo)到大腸桿菌,建立DNA克隆文庫,每個樣本分別隨機選擇160個克隆進行DNA序列測定。3.序列分類和種系分析：保守序列直接在GenBank上進行BLAST比較,然后用RDPII9.49進行細菌門類及屬類分類。≥97%一致序列確定為同一屬,用MEGA5.0進行相鄰合并分析繪制種系結(jié)構(gòu)圖。 結(jié)果：1.對照組10個樣本測序共獲得1317個16SrRNA基因序列,抗生素組4個樣本共獲得536個16S rRNA基因序列。2.細菌門水平的分類顯示兒童糞便中優(yōu)勢菌群為厚壁菌門和擬桿菌門,在對照組中分別占菌群總數(shù)的55.2%和40.9%,在抗生素組中分別占菌群總數(shù)的50.8%和42.7%,此外,兩組中均含少量變形菌門、放線菌門、棲熱菌門和未分類菌門。3.對照組和抗生素組兩組各主要門類下各屬水平的分布無明顯差異并且兩組樣本分布結(jié)構(gòu)相似。4.各樣本的菌群結(jié)構(gòu)各不相同,厚壁菌門比例從12%到85.4%不等,擬桿菌門從12.7%到83%不等。 結(jié)論：1.兒童糞便優(yōu)勢菌群由厚壁菌門(55.2%)、擬桿菌門(40.9%)組成,變形桿菌門、放線菌門和梭桿菌門共計少于5%；厚壁菌門中Faecalibacterium (53%)、 Roseburia (8.5%)和Lachnospiraceae incertae sedis (6.2%)為優(yōu)勢菌屬；擬桿菌門中Prevotella (47.2%)和Bacteroides(42.8%)為優(yōu)勢菌屬;2.不管在門或?qū)俚乃缴?兒童糞便菌群在各個體有其獨特的菌群結(jié)構(gòu)分布；3.4例一周內(nèi)使用β-內(nèi)酰胺類抗生素兒童糞便樣本菌群組成與對照組比較統(tǒng)計分析無明顯差異,這可能與分析例數(shù)少或?qū)φ战M在既往中使用抗生素有關(guān)。
[Abstract]:Objective: to investigate the composition of intestinal flora and the effect of 尾-lactam antibiotics on intestinal bacterial composition in children. Method 1: 1. Specimen collection: the fecal samples of 10 healthy children aged 3-5 years with no history of antibiotic use within one month (control group) and 4 children of the same age group who had a history of using 尾 -lactam antibiotics within one week were collected. Antibiotic group) Fecal DNA was extracted and 16s rRNA gene was amplified, the amplified product was transferred to Escherichia coli by ligation with amplified plasmid, and DNA clone library was established. 160 clones were randomly selected for DNA sequencing in each sample. Sequence classification and phylogenetic analysis: conserved sequences were compared directly with BLAST on GenBank, and then bacteria and genera were classified by RDPII9.49. 鈮，

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