摘要

       已经假设在致病细菌中发现的一些抗生素抗性基因 (ARG) 来自产生抗生素的放线菌。在这里，我们提供了支持这一假设的生物信息学和实验证据。我们确定了变形菌中的基因，包括一些病原体，这些基因似乎与已知赋予对临床重要抗生素抗性的放线菌 ARG 密切相关。此外，我们确定了最近将放线菌 ARG 水平转移到变形菌病原体的两个潜在例子。基于这一生物信息学证据，我们提出并通过实验测试了一种转移的“回带”机制，包括将载体序列从变形杆菌结合转移到放线菌，载体序列与放线菌 ARG 的重组，然后是变形杆菌的自然转化与载体夹心的 ARG。我们的结果支持存在古老的和可能是最近的 ARG 从产生抗生素的放线菌到变形菌的转移，并为明确的机制提供了证据。

       It has been hypothesized that some antibiotic resistance genes (ARGs) found in pathogenic bacteria derive from antibiotic-producing actinobacteria. Here we provide bioinformatic and experimental evidence supporting this hypothesis. We identify genes in proteobacteria, including some pathogens, that appear to be closely related to actinobacterial ARGs known to confer resistance against clinically important antibiotics. Furthermore, we identify two potential examples of recent horizontal transfer of actinobacterial ARGs to proteobacterial pathogens. Based on this bioinformatic evidence, we propose and experimentally test a ‘carry-back’ mechanism for the transfer, involving conjugative transfer of a carrier sequence from proteobacteria to actinobacteria, recombination of the carrier sequence with the actinobacterial ARG, followed by natural transformation of proteobacteria with the carrier-sandwiched ARG. Our results support the existence of ancient and, possibly, recent transfers of ARGs from antibiotic-producing actinobacteria to proteobacteria, and provide evidence for a defined mechanism.

https://www.nature.com/articles/ncomms15784