Scientists at the University of Sheffield have uncovered a new sensory capability in bacteria that may lead to innovative treatments for bacterial infections. Contrary to longstanding scientific belief, a recent study has shown that bacteria can directly sense their chemical environment across the length of their cell bodies with a high degree of precision.
The research, published in Nature Microbiology, focused on Pseudomonas aeruginosa, a pathogen identified by the World Health Organisation as a priority due to its ability to cause highly antibiotic-resistant infections in humans.
Dr William Durham, Senior Lecturer in Biological Physics at the University of Sheffield’s Department of Physics and Astronomy and senior author of the study, explained the significance of the findings. “In principle, cells can figure out whether they are moving towards or away from a nutrient source in two different ways. First, they can wander randomly and measure if the concentration increases or decreases over time. Alternatively, cells can measure changes in concentration over the length of their bodies, allowing them to directly move towards the source. Our research demonstrates that bacteria can do the latter, which was previously thought beyond their capabilities due to their tiny size.”
The study revealed that bacteria navigate surfaces towards chemical sources using tiny grappling hooks known as pili. Researchers used innovative microfluidic experiments and engineered strains of P. aeruginosa to visualise their motility systems under powerful microscopes. They discovered that these cells can compare nutrient concentrations along the length of their cell bodies, a phenomenon referred to as ‘spatial sensing.’
Dr Jamie Wheeler, a postdoctoral researcher in the University of Sheffield’s Department of Physics and Astronomy and the study’s lead author, noted, “This work overturns our understanding of how bacteria navigate and sense their environment. As such, it sheds new light on how bacteria could direct their motility during human infection and potentially how it could be manipulated by different clinical treatments.”
The discovery indicates that bacteria within localised infections may not need to move to sense changes in their chemical environment. This finding suggests new possibilities for manipulating bacterial behaviour through antimicrobial treatments. Dr Wheeler added, “As is often the case, answering one question has raised a whole new set of unknowns. Exciting new experiments are already planned to continue writing this new chapter in our understanding of how bacteria navigate through their environment.”