Relaxometry for detecting free radical generation during Bacteria's response to antibiotics

Neda Norouzi, Anggrek Citra Nusantara, Yori Ong, Thamir Hamoh, Linyan Nie, Aryan Morita, Yue Zhang, Aldona Mzyk, Romana Schirhagl*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

Free radical generation plays a key role in killing bacteria by antibiotics. However, radicals are short-lived and reactive, and thus difficult to detect for the state of the art. Here we use a technique which allows optical nanoscale magnetic resonance imaging (MRI) to detect radical generation on the scale of single bacteria. We demonstrate that the radical generation in Staphylococcus aureus increases in the presence of UV irradiation as well as vancomycin and is dependent on the antibiotic's dose. With a method based on ensembles of nitrogen vacancy (NV) centers in diamond, we were able to follow the radical formation near individual bacteria over the whole duration of the experiment to reveal the dynamics of radical generation. Using this new approach, we observed free radical concentrations within nanoscale voxels around the diamond particles and determined its exact timing depending on the antibiotic dose. Since changes in the response to antibiotics emerge in only a few bacteria of the entire population, such a single-cell approach can prove highly valuable for research into drug resistance.

Original languageEnglish
Pages (from-to)444-452
Number of pages9
JournalCarbon
Volume199
DOIs
Publication statusPublished - 31-Oct-2022

Keywords

  • Diamond relaxometry
  • Free radical
  • Bacterial response
  • Antibiotics
  • NUCLEAR-MAGNETIC-RESONANCE
  • OXIDATIVE STRESS
  • IN-VIVO
  • DIAMOND NANOPARTICLES
  • OXYGEN
  • FLUORESCENT
  • VANCOMYCIN
  • MECHANISM
  • NITROGEN
  • RELEASE

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