人們已經(jīng)對(duì)農(nóng)業(yè)動(dòng)物使用了50多年的抗生素從而改善生產(chǎn),，近日發(fā)表在PNAS雜志上的一項(xiàng)研究"In-feed antibiotic effects on the swine intestinal microbiome"證實(shí)：這可能增強(qiáng)耐抗生素基因并增加埃希氏大腸桿菌在豬糞中的散發(fā)。
Looft及其同事評(píng)估了資料中的抗生素對(duì)豬的腸道微生物群的作用,。這組作者讓一組小豬食用沒有藥的飼料,，而讓另一組食用添加了氯四環(huán)素,、磺胺甲嘧啶以及青霉素的性能增強(qiáng)混合物的飼料。
對(duì)糞樣本的遺傳分析顯示,，食用了抗生素的小豬體內(nèi)的變形菌門微生物的成員是沒有食用抗生素的小豬的10倍以上,，這特別是由于埃希氏大腸桿菌中群的增加。
另外的定量與統(tǒng)計(jì)分析表明,，與能量生產(chǎn)和轉(zhuǎn)化有關(guān)的微生物功能基因的表達(dá)在食用抗生素的豬的體內(nèi)增加,。這些食用了藥物的豬的耐抗生素基因的豐富程度和多樣性增加。這組作者說,，這些發(fā)現(xiàn)提示應(yīng)該謹(jǐn)慎地讓動(dòng)物和人類使用抗生素,，而進(jìn)一步的研究應(yīng)該把重點(diǎn)放在抗生素替代品的開發(fā)上。（生物谷Bioon.com）
doi:10.1073/pnas.1120238109
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PMID:
In-feed antibiotic effects on the swine intestinal microbiome
Torey Loofta,1, Timothy A. Johnsonb,c,1, Heather K. Allena,1, Darrell O. Baylesa, David P. Alta, Robert D. Stedtfeldb,d, Woo Jun Sulb,c, Tiffany M. Stedtfeldb, Benli Chaib, James R. Coleb, Syed A. Hashshamb,d, James M. Tiedjeb,c,2, and Thad B. Stantona,2
Antibiotics have been administered to agricultural animals for disease treatment, disease prevention, and growth promotion for over 50 y. The impact of such antibiotic use on the treatment of human diseases is hotly debated. We raised pigs in a highly controlled environment, with one portion of the littermates receiving a diet containing performance-enhancing antibiotics [chlortetracycline, sulfamethazine, and penicillin (known as ASP250)] and the other portion receiving the same diet but without the antibiotics. We used phylogenetic, metagenomic, and quantitative PCR-based approaches to address the impact of antibiotics on the swine gut microbiota. Bacterial phylotypes shifted after 14 d of antibiotic treatment, with the medicated pigs showing an increase in Proteobacteria (1–11%) compared with nonmedicated pigs at the same time point. This shift was driven by an increase in Escherichia coli populations. Analysis of the metagenomes showed that microbial functional genes relating to energy production and conversion were increased in the antibiotic-fed pigs. The results also indicate that antibiotic resistance genes increased in abundance and diversity in the medicated swine microbiome despite a high background of resistance genes in nonmedicated swine. Some enriched genes, such as aminoglycoside O-phosphotransferases, confer resistance to antibiotics that were not administered in this study, demonstrating the potential for indirect selection of resistance to classes of antibiotics not fed. The collateral effects of feeding subtherapeutic doses of antibiotics to agricultural animals are apparent and must be considered in cost-benefit analyses.
