Understanding survival and adaptation of the meningococcus bacteria in aerosol droplets
Background
Meningococcal bacteria (Neisseria meningitidis) remain an important cause of meningitis and septicaemia worldwide. Although many people make a good recovery following meningococcal infection, some will be left with life-long disabilities and others will die.
It is known that meningococcal bacteria spread from person to person by close, prolonged contact and exhalation or inhalation of droplets that contain these bacteria. Disease is caused when these inhaled bacteria are able to enter the blood stream and central nervous system.
Despite our understanding of how these bacteria cause disease once they are inside the body, almost nothing is known about how they survive and adapt during transmission from human to human in aerosol droplets. The ability of bacteria to adapt during transmission will influence how likely they are to infect an individual following inhalation of the aerosol.
Transmission will depend on bacterial characteristics together with environmental factors such as temperature, humidity and droplet size.
The aims of this research are to:
- Investigate the impact of temperature and humidity on the survival of meningococcal bacteria in respiratory droplets
- Determine how the outer surface (capsule) of the bacterial cell contributes to survival in respiratory droplets
- Understand the genetic changes that occur in meningococcal bacteria during transmission
These aims will be achieved using a state-of-the-art droplet generation and control system developed in Bristol, combined with technology to investigate genetic changes in bacteria.
This four-year project will support PhD student Mia Dierks to undertake the research, supervised by a multi-disciplinary team of experts in aerosol science, molecular microbiology and clinical sciences.
Potential impact
The results of this research could help to improve vaccine development and inform the design of new drugs. They could also help to modify infection control procedures, including engineering strategies such as heating or air conditioning in public spaces, which could reduce the survival and transmission rates of airborne bacteria.
Progress so far
October 2024
Survival and Adaptation of the Meningococcus in Aerosol Droplets.
Mia and the team have determined that the survival of N. meningitidis (meningococcal bacteria) in the air is partly dependent on relative humidity as all tested strains showed improved survival as relative humidity was increased. They observed a significant drop in survival after just 15 seconds of aerosolisation, with some strains showing little survival after 5 minutes. The team have also begun to unravel the mechanisms that drive death of this bacteria in the air, as the addition of an antioxidant significantly increased survival.
Over the next year, the team will undertake further work to understand this mechanism by using different antioxidants commonly found in human saliva. They will also use real saliva to aerosolise bacteria in.
October 2023
Mia Dierks Treece has just joined the team to commence her PhD studies. This first year will consist of academic training and supervision. In the three following years of this project, Mia will be working on each of the aims of this research.
Introducing PhD Student Mia Dierks Treece
During my time as an undergraduate student, I studied Cellular and Molecular Medicine at the University of Bristol, covering topics ranging from cancer to microbiology. My passion for research first emerged during my third year where I completed a year in industry with Haleon focusing on oral biofilms.
I was first introduced to meningococcal bacteria in the context of aerosol science during my final year undergraduate project supervised by Darryl Hill. This paved the way for me to begin my current PhD project in understanding the complex mechanisms by which Neisseria meningitidis can survive in the air, using specialist equipment developed here in Bristol.
More information
If you would like more information about this project, or our research in general, please contact research@meningitisnow.org.