State Key Laboratory of Microbial metabolism, and School of Life Science & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, P.R. China.
Institute of Bio-medicine, Shanghai Jiao Da Onlly Company Limited, Shanghai, 200233, P. R. China.
Sci Rep. 2017 Jul 24;7(1):6267. doi: 10.1038/s41598-017-06595-0.
Due to tetracycline abuse, the safe bifidobacteria in the human gastrointestinal intestinal tract (GIT) may serve as a reservoir of tetracycline resistance genes. In the present investigation of 92 bifidobacterial strains originating from the human GIT, tetracycline resistance in 29 strains was mediated by the tet(W), tet(O) or tet(S) gene, and this is the first report of tet(O)- and tet(S)-mediated tetracycline resistance in bifidobacteria. Antibiotic resistance genes harbored by bifidobacteria are transferred from other bacteria. However, the characteristics of the spread and integration of tetracycline resistance genes into the human intestinal bifidobacteria chromosome are poorly understood. Here, conserved sequences were identified in bifidobacterial strains positive for tet(W), tet(O), or tet(S), including the tet(W), tet(O), or tet(S) and their partial flanking sequences, which exhibited identity with the sequences in multiple human intestinal pathogens, and genes encoding 23 S rRNA, an ATP transporter, a Cpp protein, and a membrane-spanning protein were flanking by the 1920-bp tet(W), 1920-bp tet(O), 1800-bp tet(O) and 252-bp tet(S) in bifidobacteria, respectively. These findings suggest that tetracycline resistance genes harbored by human intestinal bifidobacteria might initially be transferred from pathogens and that each kind of tetracycline resistance gene might tend to insert in the vicinity of specific bifidobacteria genes.
由于四环素滥用，人类胃肠道（GIT）中的安全双歧杆菌可能成为四环素耐药基因的库。在本次对 92 株双歧杆菌的研究中，29 株双歧杆菌的四环素耐药性是由 tet(W)、tet(O)或 tet(S)基因介导的，这是双歧杆菌中首次报道 tet(O)和 tet(S)介导的四环素耐药性。双歧杆菌携带的抗生素耐药基因是从其他细菌转移而来的。然而，四环素耐药基因在人类肠道双歧杆菌染色体中的传播和整合的特征还了解甚少。在这里，在 tet(W)、tet(O)或 tet(S)阳性的双歧杆菌菌株中鉴定出了保守序列，包括 tet(W)、tet(O)或 tet(S)及其部分侧翼序列，它们与多种人类肠道病原体的序列具有同源性，并且编码 23SrRNA、ATP 转运蛋白、Cpp 蛋白和跨膜蛋白的基因被 1920-bp 的 tet(W)、1920-bp 的 tet(O)、1800-bp 的 tet(O)和 252-bp 的 tet(S)分别侧翼。这些发现表明，人类肠道双歧杆菌中携带的四环素耐药基因最初可能是从病原体转移而来的，并且每种四环素耐药基因可能倾向于插入特定双歧杆菌基因附近。
