Multimodal chemical imaging of molecular messengers in emerging Pseudomonas aeruginosa bacterial communities
Multimodal chemical imaging of molecular messengers in emerging Pseudomonas aeruginosa bacterial communities
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DOI：
10.1039/c5an01149c
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发表时间：
2015-01-01
期刊：
影响因子：
4.2
通讯作者：
Bohn, Paul W.
中科院分区：
文献类型：
--
作者：
Baig, Nameera F.;Dunham, Sage J. B.;Bohn, Paul W.
结合两种无标记分子成像技术，共聚焦拉曼显微镜(CRM)和二次离子质谱仪(SIMS)，原位表征了喹诺酮类代谢物和信号分子在致病菌铜绿假单胞菌群落中的时空分布。这些细菌的浮游和生物膜生长模式之间存在着巨大的分子差异。我们观察到在铜绿假单胞菌的早期生物膜和菌群中有模式聚集和高丰度的N-氧化物喹啉，而这些分泌成分在浮游细胞和琼脂平板菌落中的浓度低于CRM和SIMS的检测限值。根据共局域异构体对4-羟基-2-庚基喹啉-N-氧化物(HQNO)/2-庚基-3-羟基喹诺酮(PQS)和4-羟基-2-壬基喹啉-N-氧化物(NQNO)/2-壬基-羟基喹诺酮(C9-PQs)的振动指纹图谱的差异，结合主成分分析(PCA)，说明了该技术如何用于指导串联MS和串联MS成像分析。由于N-氧化物喹啉类化合物普遍存在并在生物膜中早期表达，这些分析物对早期生物膜的形成以及铜绿假单胞菌微生物群落的生长和组织可能是至关重要的。这项研究强调了使用多模式分子成像来研究复杂生物系统的优势。
Two label-free molecular imaging techniques, confocal Raman microscopy (CRM) and secondary ion mass spectrometry (SIMS), are combined for in situ characterization of the spatiotemporal distributions of quinolone metabolites and signaling molecules in communities of the pathogenic bacterium Pseudomonas aeruginosa. Dramatic molecular differences are observed between planktonic and biofilm modes of growth for these bacteria. We observe patterned aggregation and a high abundance of N-oxide quinolines in early biofilms and swarm zones of P. aeruginosa, while the concentrations of these secreted components in planktonic cells and agar plate colonies are below CRM and SIMS detection limits. CRM, in conjunction with principal component analysis (PCA) is used to distinguish between the two co-localized isomeric analyte pairs 4-hydroxy-2-heptylquinoline-N-oxide (HQNO)/2-heptyl-3-hydroxyquinolone (PQS) and 4-hydroxy-2-nonylquinoline-N-oxide (NQNO)/2-nonyl-hydroxyquinolone (C9-PQS) based on differences in their vibrational fingerprints, illustrating how the technique can be used to guide tandem-MS and tandem-MS imaging analysis. Because N-oxide quinolines are ubiquitous and expressed early in biofilms, these analytes may be fundamentally important for early biofilm formation and the growth and organization of P. aeruginosa microbial communities. This study underscores the advantages of using multimodal molecular imaging to study complex biological systems.