Coculture of Staphylococcus aureus with Pseudomonas aeruginosa Drives S-aureus towards Fermentative Metabolism and Reduced Viability in a Cystic Fibrosis Model
Coculture of Staphylococcus aureus with Pseudomonas aeruginosa Drives S-aureus towards Fermentative Metabolism and Reduced Viability in a Cystic Fibrosis Model
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DOI：
10.1128/jb.00059-15
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发表时间：
2015-07-01
影响因子：
3.2
通讯作者：
O'Toole, George A.
中科院分区：
文献类型：
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作者：
Filkins, Laura M.;Graber, Jyoti A.;O'Toole, George A.
囊性纤维化患者的气道定植有不同的细菌群落，这些细菌群落在儿童时期和成年早期动态变化。金黄色葡萄球菌是儿童早期最常见的病原体，但在青少年后期和成年早期，微生物组成发生变化，导致铜绿假单胞菌群落在50%的成年人中占主导地位。我们建立了一个稳定的铜绿假单胞菌和S.金黄色葡萄球菌对Delta F508囊性纤维化跨膜传导调节因子（CFTR）突变纯合的人支气管上皮细胞单层的作用，以更好地模拟这种相互作用的机制。我们发现，铜绿假单胞菌驱动的S。从有氧呼吸到发酵的金黄色葡萄球菌表达谱。这种转变取决于铜绿假单胞菌产生的2-庚基-4-羟基喹啉N-氧化物（HQNO）和铁载体。此外，S.金黄色葡萄球菌产生的乳酸是铜绿假单胞菌优先消耗的碳源，而不是中等供应的葡萄糖。我们发现，最初S。金黄色葡萄球菌和铜绿假单胞菌共存;然而，过度共培养铜绿假单胞菌减少了S.金黄色葡萄球菌活力，也以HQNO和铜绿假单胞菌铁载体依赖性方式。有趣的是，S.金黄色葡萄球菌小菌落变异体（SCV）遗传突变株，其电子传递链有缺陷，与其野生型亲本菌株相比，铜绿假单胞菌的杀伤作用降低;因此，SCV可能提供了S.在铜绿假单胞菌的存在下的金黄色葡萄球菌。我们认为铜绿假单胞菌对S.金黄色葡萄球菌是多因素的，需要HQNO和铜绿假单胞菌铁载体以及其他遗传、环境和营养因素。重要提示患有囊性纤维化的个体，金黄色葡萄球菌是儿童时期的主要呼吸道病原体。在成年期，铜绿假单胞菌占主导地位，并与更差的患者结局相关。铜绿假单胞菌战胜或杀死S.金黄色葡萄球菌还没有被很好地理解。我们描述了一种在体外双菌种共培养系统的囊性纤维化衍生的气道细胞，模型与囊性纤维化患者的相互作用。此外，我们表明，分子产生的铜绿假单胞菌相加诱导转变的S。金黄色葡萄球菌的代谢从有氧呼吸到发酵，最终导致S.金黄色葡萄球菌活力。阐明铜绿假单胞菌群落优势的分子机制可以提供新的治疗靶点和方法来阻止这种微生物群落转变和随后的患者恶化。
The airways of patients with cystic fibrosis are colonized with diverse bacterial communities that change dynamically during pediatric years and early adulthood. Staphylococcus aureus is the most prevalent pathogen during early childhood, but during late teens and early adulthood, a shift in microbial composition occurs leading to Pseudomonas aeruginosa community predominance in similar to 50% of adults. We developed a robust dual-bacterial in vitro coculture system of P. aeruginosa and S. aureus on monolayers of human bronchial epithelial cells homozygous for the Delta F508 cystic fibrosis transmembrane conductance regulator (CFTR) mutation to better model the mechanisms of this interaction. We show that P. aeruginosa drives the S. aureus expression profile from that of aerobic respiration to fermentation. This shift is dependent on the production of both 2-heptyl-4-hydroxyquinoline N-oxide (HQNO) and siderophores by P. aeruginosa. Furthermore, S. aureus-produced lactate is a carbon source that P. aeruginosa preferentially consumes over medium-supplied glucose. We find that initially S. aureus and P. aeruginosa coexist; however, over extended coculture P. aeruginosa reduces S. aureus viability, also in an HQNO-and P. aeruginosa siderophore-dependent manner. Interestingly, S. aureus small-colony-variant (SCV) genetic mutant strains, which have defects in their electron transport chain, experience reduced killing by P. aeruginosa compared to their wild-type parent strains; thus, SCVs may provide a mechanism for persistence of S. aureus in the presence of P. aeruginosa. We propose that the mechanism of P. aeruginosa-mediated killing of S. aureus is multifactorial, requiring HQNO and P. aeruginosa siderophores as well as additional genetic, environmental, and nutritional factors.IMPORTANCEIndividuals with cystic fibrosis, Staphylococcus aureus is the primary respiratory pathogen during childhood. During adulthood, Pseudomonas aeruginosa predominates and correlates with worse patient outcome. The mechanism(s) by which P. aeruginosa outcompetes or kills S. aureus is not well understood. We describe an in vitro dual-bacterial species coculture system on cystic fibrosis-derived airway cells, which models interactions relevant to patients with cystic fibrosis. Further, we show that molecules produced by P. aeruginosa additively induce a transition of S. aureus metabolism from aerobic respiration to fermentation and eventually lead to loss of S. aureus viability. Elucidating the molecular mechanisms of P. aeruginosa community predominance can provide new therapeutic targets and approaches to impede this microbial community transition and subsequent patient worsening.