Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.
Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.
J Antimicrob Chemother. 2020 Oct 1;75(10):2797-2803. doi: 10.1093/jac/dkaa284.
The emergence of plasmid-mediated tet(X3)/tet(X4) genes is threatening the role of tigecycline as a last-resort antibiotic to treat clinical infections caused by XDR bacteria. Considering the possible public health threat posed by tet(X) and its variants [which we collectively call 'tet(X) genes' in this study], global monitoring and surveillance are urgently required.
Here we conducted a worldwide survey of the global distribution and spread of tet(X) genes.
We analysed a comprehensive dataset of bacterial genomes in conjunction with surveillance data from our laboratory and the NCBI database, as well as sufficient metadata to characterize the results.
The global distribution features of tet(X) genes were revealed. We clustered three types of genetic backbones of tet(X) genes embedded or transferred in bacterial genomes. Our pan-genome analyses revealed a large genetic pool composed of tet(X)-carrying sequences. Moreover, phylogenetic trees of tet(X) genes and tet(X)-like proteins were built.
To the best of our knowledge, our results provide the first view of the global distribution of tet(X) genes, demonstrate the features of tet(X)-carrying fragments and highlight the possible evolution of tigecycline-inactivation enzymes in diverse bacterial species and habitats.
质粒介导的 tet(X3)/tet(X4) 基因的出现，威胁到替加环素作为治疗 XDR 细菌引起的临床感染的最后手段抗生素的作用。考虑到 tet(X)及其变体（在本研究中我们统称“tet(X) 基因”）可能对公共卫生造成的威胁，迫切需要进行全球监测和监测。
本研究旨在对 tet(X) 基因在全球的分布和传播进行调查。
我们分析了一个包含大量细菌基因组的综合数据集，结合我们实验室和 NCBI 数据库的监测数据，以及足够的元数据来对结果进行特征描述。
揭示了 tet(X) 基因的全球分布特征。我们对嵌入或转移到细菌基因组中的 tet(X) 基因的三种遗传骨架进行了聚类。我们的泛基因组分析揭示了一个由携带 tet(X)的序列组成的大型遗传库。此外，还构建了 tet(X) 基因和 tet(X)-样蛋白的系统发育树。
据我们所知，我们的研究结果首次提供了 tet(X) 基因在全球的分布情况，展示了携带 tet(X)的片段的特征，并强调了不同细菌物种和生境中替加环素失活酶的可能进化。
