An in vitro model for the cultivation of polymicrobial biofilms under continuous-flow conditions

The airways of people with cystic fibrosis (CF) are often chronically colonised with a diverse array of bacterial and fungal species. However, little is known about the relative partitioning of species between the planktonic and biofilm modes of growth in the airways. Existing <i>in vivo</i> and <i>in vitro</i> models of CF airway infection are ill-suited for the long-term recapitulation of mixed microbial communities. We have described a simple, continuous-flow model for the cultivation of polymicrobial biofilms and planktonic cultures on different substrata (submitted to the NC3Rs F1000 research gateway). Our data (deposited here) provide evidence for inter-species antagonism and synergism in biofilm ecology. We further show that the type of substratum on which the biofilms grow has a profound influence on their species composition. This happens without any major alteration in the composition of the surrounding steady-state planktonic community. Our experimentally-tractable model enables the systematic study of planktonic and biofilm communities under conditions that are nutritionally reminiscent of the CF airway microenvironment, something not possible using any existing <i>in vivo</i> models of CF airway infection.

囊性纤维化（cystic fibrosis, CF）患者的气道常被多种多样的细菌与真菌类群长期定植。然而，目前学界对CF气道内物种在浮游态（planktonic）与生物被膜（biofilm）两种生长模式下的相对分布情况仍知之甚少。现有的CF气道感染体内（in vivo）与体外（in vitro）模型，均无法长期复现混合微生物群落的真实生长状态。本研究团队已开发出一款简易的连续流动模型，可在不同基质（substrata）上培养多微生物生物被膜与浮游培养物（该模型已提交至NC3Rs F1000研究平台）。本数据集收录的数据证实了生物被膜生态学中存在种间拮抗与协同作用；进一步研究表明，生物被膜附着的基质类型对其物种组成具有显著影响，且该影响不会导致周边稳态浮游群落的组成发生明显改变。这款实验可操作性强的模型，能够在营养条件模拟CF气道微环境的场景下，系统性研究浮游态与生物被膜态微生物群落——这是现有CF气道感染体内模型无法实现的研究方向。