Data for: Antibiotic-degrading resistance changes bacterial community structure via species-specific responses

Some bacterial resistance mechanisms degrade antibiotics, potentially
protecting neighbouring susceptible cells from antibiotic exposure. We do
not yet understand how such effects influence bacterial communities of
more than two species, which are typical in nature. Here, we used
experimental multispecies communities to test the effects of clinically
important pOXA-48-plasmid-encoded resistance on community-level responses
to antibiotics. We found that resistance in one community member reduced
antibiotic inhibition of other species, but some benefitted more than
others. Further experiments with supernatants and pure-culture growth
assays showed the susceptible species profiting most from detoxification
were those that grew best at degraded antibiotic concentrations (greater
than zero, but lower than the starting concentration). This pattern was
also observed on agar surfaces, and the same species also showed
relatively high survival compared to most other species during the initial
high-antibiotic phase. By contrast, we found no evidence of a role for
higher-order interactions or horizontal plasmid transfer in
community-level responses to detoxification in our experimental
communities. Our findings suggest carriage of an antibiotic-degrading
resistance mechanism by one species can drastically alter community-level
responses to antibiotics, and the identities of the species that profit
most from antibiotic detoxification are predicted by their intrinsic
ability to survive and grow at changing antibiotic concentrations.

部分细菌耐药机制可降解抗生素，从而潜在保护邻近的敏感细胞免受抗生素暴露。目前我们尚不清楚此类效应会如何影响自然界中普遍存在的多物种细菌群落。本研究通过实验性多物种群落，探究临床重要的pOXA-48质粒编码的耐药性（pOXA-48-plasmid-encoded resistance）对群落层面抗生素应答的影响。我们发现，单个群落成员的耐药性可降低其他物种受到的抗生素抑制作用，但不同物种的获益程度存在差异。进一步通过上清液实验与纯培养生长实验证实，从抗生素降解中获益最多的敏感物种，正是那些在降解后的抗生素浓度（浓度大于零，但低于初始浓度）下生长能力最强的物种。该模式在琼脂平板表面也得到了验证；同时，在初始高抗生素浓度阶段，与多数其他物种相比，这类物种的存活率相对更高。与之相对，本研究的实验群落中未发现高阶交互作用或水平质粒转移参与群落对抗生素降解应答的证据。我们的研究结果表明，单个物种携带抗生素降解型耐药机制，可显著改变群落层面的抗生素应答模式，而从抗生素降解中获益最多的物种身份，可通过其在变化的抗生素浓度下存活与生长的内在能力进行预测。