Imaging Isotopically Labeled Bacteria at the Single-Cell Level Using High-Resolution Optical Infrared Photothermal Spectroscopy.
Cassio LimaHowbeer MuhamadaliYun XuMustafa KansizRoyston GoodacrePublished in: Analytical chemistry (2021)
We report that the cellular uptake of stable isotope-labeled compounds by bacteria can be probed at the single-cell level using infrared spectroscopy, and this monitors the chemical vibrations affected by the incorporation of "heavy" atoms by cells and thus can be used to understand microbial systems. This presents a significant advancement as most studies have focused on evaluating communities of cells due to the poor spatial resolution achieved by classical infrared microspectrometers, and to date, there is no study evaluating the incorporation of labeled compounds by bacteria at single-cell levels using infrared spectroscopy. The development of new technologies and instrumentations that provide information on the metabolic activity of a single bacterium is critical as this will allow for a better understanding of the interactions between microorganisms as well as the function of individual members and their interactions in different microbial communities. Thus, the present study demonstrates the ability of a novel far-field infrared imaging technique, optical photothermal infrared (O-PTIR) spectroscopy, as a tool to monitor the uptake of 13C-glucose and 15N-ammonium chloride by Escherichia coli bacteria at single-cell levels using spectral signatures recorded via single-point and imaging modes. An additional novelty is that imaging was achieved using six vibrational bands in the amide I and II regions, which were analyzed with chemometrics by employing partial least squares-discriminant analysis to predict 13C/12C and 15N/14N simultaneously.
Keyphrases
- high resolution
- single cell
- rna seq
- escherichia coli
- induced apoptosis
- high throughput
- mass spectrometry
- high speed
- photodynamic therapy
- cell cycle arrest
- single molecule
- microbial community
- healthcare
- blood pressure
- computed tomography
- gene expression
- cancer therapy
- magnetic resonance imaging
- oxidative stress
- type diabetes
- pseudomonas aeruginosa
- insulin resistance
- cell death
- social media
- adipose tissue
- positron emission tomography