Fluorescent probes shine a light on bacterial resistance

23 November 2020

Researchers are using tiny fluorescent probes to investigate how and why bacteria are becoming resistant to antibiotics.

An international collaboration led by Dr Mark Blaskovich is using fluorescent probes derived from antibiotics to understand how we can develop better ways to kill bacteria more effectively, especially those that are becoming resistant.

In a research paper published in Antibiotics Awareness Week (18-24 November), the collaboration, which includes the University of Exeter (UK) and Universite Paris-Saclay (France), used the probes to monitor the interactions of antibiotics with hundreds to thousands of individual bacteria.

Video: Uptake of roxithromycin fluorescent probe by individual S. aureus (first 17 seconds) or E. coli bacteria within a microfluidics chip, as shown by University of Exeter collaborators Urszula Łapińska and Stefano Pagliara.

Dr Blaskovich said measuring the antibiotic response at the level of an individual bacterium can help to uncover different ways in which bacteria are developing resistance to antibiotics, something you normally don’t see when studying bacterial populations as a whole.

“By using an antibiotic tagged with a fluorescent probe, we could see the rate at which the antibiotic was being taken up by the bacteria,” Dr Blaskovich said.

“While one group of bacteria started glowing at the same time, indicating they were taking up the bacteria simultaneously, another group was very variable as to when or if they picked up any of the probes.

“This variability might explain why these bacteria are able to survive – they aren’t picking up any of the antibiotics at all.”

While the researchers don’t yet know why these bacteria aren’t being affected by antibiotics, it gives them an idea as to avenues to explore to figure out the mechanisms bacteria are using.

Dr Blaskovich hopes the findings will inspire further studies to understand why some bacteria are able to resist antibiotics, and lead to better antibiotics that can kill bacteria more effectively.

Dr Mark Blaskovich is an antibiotic hunter and Director of the Centre for Superbug Solutions, and has been developing new antibiotics to treat drug-resistant pathogens and using modified antibiotics to detect bacterial infections.

The study was published in RSC Chemical Biology and was supported by organisations including the Wellcome Trust, National Health and Medical Research Council and the Australian Cancer Research Foundation.