Microbial Genome Research Center, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
FEMS Microbiol Lett. 2012 Nov;336(1):11-6. doi: 10.1111/j.1574-6968.2012.02647.x. Epub 2012 Sep 18.
The human gut microbiota has a high density of bacteria that are considered a reservoir for antibiotic resistance genes (ARGs). In this study, one fosmid metagenomic library generated from the gut microbiota of four healthy humans was used to screen for ARGs against seven antibiotics. Eight new ARGs were obtained: one against amoxicillin, six against d-cycloserine, and one against kanamycin. The new amoxicillin resistance gene encodes a protein with 53% identity to a class D β-lactamase from Riemerella anatipestifer RA-GD. The six new d-cycloserine resistance genes encode proteins with 73-81% identity to known d-alanine-d-alanine ligases. The new kanamycin resistance gene encodes a protein of 274 amino acids with an N-terminus (amino acids 1-189) that has 42% identity to the 6'-aminoglycoside acetyltransferase [AAC(6')] from Enterococcus hirae and a C-terminus (amino acids 190-274) with 35% identity to a hypothetical protein from Clostridiales sp. SSC/2. A functional study on the novel kanamycin resistance gene showed that only the N-terminus conferred kanamycin resistance. Our results showed that functional metagenomics is a useful tool for the identification of new ARGs.
人类肠道微生物群中存在大量被认为是抗生素耐药基因 (ARGs) 储库的细菌。在这项研究中，使用从 4 名健康人肠道微生物群中生成的一个 fosmid 宏基因组文库来筛选针对 7 种抗生素的 ARGs。获得了 8 个新的 ARGs：1 个针对阿莫西林，6 个针对 D-环丝氨酸，1 个针对卡那霉素。新的阿莫西林耐药基因编码的蛋白与来自 Riemerella anatipestifer RA-GD 的 D 类β-内酰胺酶具有 53%的同一性。6 个新的 D-环丝氨酸耐药基因编码的蛋白与已知的 D-丙氨酸-D-丙氨酸连接酶具有 73-81%的同一性。新的卡那霉素耐药基因编码一个由 274 个氨基酸组成的蛋白，其 N 端（氨基酸 1-189）与 Enterococcus hirae 的 6'-氨基糖苷乙酰转移酶 [AAC(6')] 具有 42%的同一性，C 端（氨基酸 190-274）与 Clostridiales sp. SSC/2 的一个假设蛋白具有 35%的同一性。对新的卡那霉素耐药基因的功能研究表明，只有 N 端赋予了卡那霉素耐药性。我们的结果表明，功能宏基因组学是鉴定新的 ARGs 的有用工具。
