Gram‐Typing Using Conjugated Oligoelectrolytes

Abstract

It is shown that Gram‐type differentiation, an essential tool in microbiology, can now be easily accomplished by using the chain‐elongated conjugated oligoelectrolyte COE‐S6. Specifically, COE‐S6 can be used as a fluorescent membrane probe that distinguishes between Gram‐negative and Gram‐positive bacteria in a single step. Confocal microscopy of labeled microorganisms and differential scanning calorimetry with phospholipid‐ and lipopolysaccharide‐containing model membranes suggest that lipopolysaccharides impede COE‐S6 membrane intercalation in Gram‐negative bacteria. Both Gram‐types within a mixture are discretely labeled by counterstaining COE‐S6 with the nonspecific and lipophilic membrane probe FM 4–64. This single‐step procedure allows for the in situ visualization of individual Gram‐types in complex polymicrobial biofilms. Given that COE‐S6 fluorescence intensity increases considerably post intercalation, it can be used for the detection of Gram‐positive bacteria by the naked eye. COE‐S6 does not inhibit bacterial growth and is simple to use, making it a promising membrane‐specific fluorescent probe.

Document Details

Document Type
Pub Defense Publication
Publication Date
Aug 19, 2020
Source ID
10.1002/adfm.202004068

Entities

People

  • Alex S. Moreland
  • Bo Liedberg
  • Cheng Zhou
  • Geraldine W. N. Chia
  • Guillermo C. Bazan
  • James C. S. Ho
  • Jamie Hinks
  • Lin Ruan
  • Staffan Kjelleberg

Organizations

  • Ministry of Education
  • Nanyang Technological University
  • National University of Singapore
  • The Institute for Collaborative Biotechnologies
  • University of California, Santa Barbara
  • Yusuf Hamied Department of Chemistry

Tags

Fields of Study

  • Biology

Readers

  • Microbial Pathology
  • Molecular and Cellular Biochemistry
  • Naval Engineering and Maritime Security

Technology Areas

  • Biotechnology
  • Biotechnology - Cancer Biotech