Yuan Yang, Li Jing, Lin Jiafu, Pan Wenjuan, Chu Yiwen, Prithiviraj Balakrishnan, Guo Yidong, Wang Xinrong, Zhao Kelei
Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, Sichuan, 610052, P. R. China.
Marine Bio-products Research Laboratory, Department of Plant, Food and Environmental Sciences, Dalhousie University, Truro, B2N 5E3, NS, Canada.
J Microbiol. 2021 Jan;59(1):29-40. doi: 10.1007/s12275-021-0478-0. Epub 2020 Dec 23.
The Gram-negative pathogen Pseudomonas aeruginosa adopts several elaborate strategies to colonize a wide range of natural or clinical niches and to overcome the neighboring bacterial competitors in polymicrobial communities. However, the relationship and interaction mechanism of P. aeruginosa with other bacterial pathogens remains largely unexplored. Here we explore the interaction dynamics of P. aeruginosa and Escherichia coli, which frequently coinfect the lungs of immunocompromised hosts, by using a series of on-plate proximity assays and RNA-sequencing. We show that the extracellular products of P. aeruginosa can inhibit the growth of neighboring E. coli and induce a large-scale of transcriptional reprogramming of E. coli, especially in terms of cellular respiration-related primary metabolisms and membrane components. In contrast, the presence of E. coli has no significant effect on the growth of P. aeruginosa in short-term culture, but causes a dysregulated expression of genes positively controlled by the quorum-sensing (QS) system of P. aeruginosa during subsequent pairwise culture. We further demonstrate that the divergent QS-regulation of P. aeruginosa may be related to the function of the transcriptional regulator PqsR, which can be enhanced by E. coli culture supernatant to increase the pyocyanin production by P. aeruginosa in the absence of the central las-QS system. Moreover, the extracellular products of E. coli promote the proliferation and lethality of P. aeruginosa in infecting the Caenorhabditis elegans model. The current study provides a general characterization of the extracellular products-mediated interactions between P. aeruginosa and E. coli, and may facilitate the understanding of polymicrobial infections.
革兰氏阴性病原体铜绿假单胞菌采用多种精妙策略来定殖于广泛的自然或临床生态位，并在多微生物群落中战胜邻近的细菌竞争者。然而，铜绿假单胞菌与其他细菌病原体之间的关系及相互作用机制在很大程度上仍未得到探索。在此，我们通过一系列平板邻近试验和RNA测序，探究了经常共同感染免疫受损宿主肺部的铜绿假单胞菌和大肠杆菌之间的相互作用动态。我们发现，铜绿假单胞菌的胞外产物能够抑制邻近大肠杆菌的生长，并诱导大肠杆菌进行大规模的转录重编程，尤其是在与细胞呼吸相关的初级代谢和膜成分方面。相比之下，在短期培养中，大肠杆菌的存在对铜绿假单胞菌的生长没有显著影响，但在随后的共培养过程中，会导致铜绿假单胞菌群体感应（QS）系统正向调控的基因表达失调。我们进一步证明，铜绿假单胞菌不同的QS调控可能与转录调节因子PqsR的功能有关，在缺乏核心las-QS系统的情况下，大肠杆菌培养上清液可增强该调节因子的功能，从而增加铜绿假单胞菌的绿脓菌素产量。此外，大肠杆菌的胞外产物在感染秀丽隐杆线虫模型时促进了铜绿假单胞菌的增殖和致死性。本研究对铜绿假单胞菌和大肠杆菌之间胞外产物介导的相互作用进行了全面表征，可能有助于理解多微生物感染。
