Data from: Ecology determines how low antibiotic concentration impacts community composition and horizontal transfer of resistance genes

Low concentrations of antibiotics have numerous effects on bacteria. However, it is unknown whether ecological factors such as trophic interactions and spatial structuring influence the effects of low concentrations of antibiotics on multispecies microbial communities. Here, we address this question by investigating the effects of low antibiotic concentration on community composition and horizontal transfer of an antibiotic resistance plasmid in a 62-strain bacterial community in response to manipulation of the spatial environment and presence of predation. The strong effects of antibiotic treatment on community composition depend on the presence of predation and spatial structuring that have strong community effects on their own. Overall, we find plasmid transfer to diverse recipient taxa. Plasmid transfer is likely to occur to abundant strains, occurs to a higher number of strains in the presence of antibiotic, and also occurs to low-abundance strains in the presence of spatial structures. These results fill knowledge gaps concerning the effects of low antibiotic concentrations in complex ecological settings.

低浓度抗生素可对细菌产生多种作用效应。然而，诸如营养级相互作用与空间结构这类生态因子，是否会影响低浓度抗生素对多物种微生物群落的作用效应，目前仍不明确。本研究通过在空间环境操控与捕食者存在条件下，针对由62个菌株组成的细菌群落，探究低浓度抗生素对群落组成以及抗生素抗性质粒（antibiotic resistance plasmid）水平转移的影响，以此解答上述问题。研究发现，抗生素处理对群落组成的显著影响，依赖于捕食者存在与空间结构这两个本身即可对群落产生强烈作用的因子。总体而言，本研究观察到质粒可向多种受体类群发生转移：质粒转移更易发生于丰度较高的菌株；在抗生素存在的条件下，可发生转移的菌株数量更多；而在存在空间结构的情况下，质粒也可向低丰度菌株发生转移。本研究结果填补了低浓度抗生素在复杂生态环境中作用效应相关的认知空白。