Tazzyman Samuel J, Bonhoeffer Sebastian
Theoretical Biology Group, Institute of Integrative Biology (IBZ), ETH Zürich, Universitätstrasse 16, 8092, Zürich, Switzerland.
Evolution. 2014 Jul;68(7):2066-78. doi: 10.1111/evo.12423. Epub 2014 May 21.
Antibiotic resistance provides evolutionary rescue for bacterial populations under the threat of extinction through antibiotics. It can arise de novo through mutation in the population, or be obtained from other bacterial populations via the transfer of a resistance-conferring plasmid. We use stochastic modeling methods to establish whether the most likely source of rescue is via a plasmid or via the chromosome, and show that contrary to what is assumed plasmids are not necessarily beneficial locations for resistance genes. Competition at the plasmid level of selection is of great importance-the spread of a resistant plasmid in the population can be slowed or entirely stopped by a nonresistant version of the same plasmid. We suggest that future studies on antibiotic-resistant plasmids should explicitly consider competition at this level of selection.
抗生素耐药性为面临抗生素灭绝威胁的细菌种群提供了进化拯救。它可以通过种群中的突变重新产生，或者通过赋予抗性的质粒转移从其他细菌种群中获得。我们使用随机建模方法来确定最有可能的拯救来源是通过质粒还是通过染色体，并表明与通常假设的相反，质粒不一定是抗性基因的有益位置。质粒水平的选择竞争非常重要——抗性质粒在种群中的传播可以被相同质粒的非抗性版本减缓或完全阻止。我们建议未来关于抗生素抗性质粒的研究应明确考虑这一选择水平的竞争。
