A new study by a team of researchers that includes University of Notre Dame scientists Joshua Shrout and Mark Alber provides new insights into the behavior of an important bacterial pathogen. Alber, who is the Vincent J. Duncan Family Professor of Applied Mathematics, and Schrout, an associate professor of civil and environmental engineering and earth sciences, studied Pseudomonas aeruginosa, an opportunistic pathogen responsible for both acute and persistent infections.
"While this ubiquitous environmental bacterium rarely infects healthy people, it is a common pathogen among susceptible populations, such as individuals with cystic fibrosis, burn victims, ventilator patients, and those who have had intestinal reconstruction," Shrout says. "Pseudomonas aeruginosa is among the most common hospital-acquired infection pathogens and causes of death for intensive care unit patients."
The researchers investigated, using combination of experiments and computational modeling, how bacteria swarm in groups containing millions of cells.
"We show in this paper that appendages of this bacterium called 'pili' link together to alter group motion and give swarming groups a form of braking power," Alber says. "These bacterial swarms are able to change their motion as a group to avoid toxins. We showed this by demonstrating that bacteria with pili will avoid an area containing antibiotic--but cells without these pili do not slow their motion, swarm into the antiobiotic region, and are killed."
Although the study focused on Pseudomonas aeruginosa, the results potentially offer insights into the behavior of other bacteria.
"This is a very fundamental discovery that gives us insight into the response and control of bacteria that alter their behavior as an entire group," Shrout says. This knowledge may be useful to understand how pathogens and other bacteria can evade compounds we might use to control them and advance our understanding of how some infections become so difficult to cure."
"The next steps are to more specifically determine how individual cells are behaving in these swarming groups to detail how they coordinate their motion and then apply this knowledge to understand colonization of different types of surfaces such as human cells or medical plastics," Alber says.
The study appears in the Proceedings of the National Academy of Sciences (PNAS). The research was funded by a grant from the National Institutes of Health (NIH).
Source: University of Notre Dame
How Contaminated Is Your Stretcher? The Hidden Risks on Hospital Wheels
July 3rd 2025Despite routine disinfection, hospital surfaces, such as stretchers, remain reservoirs for harmful microbes, according to several recent studies. From high-touch areas to damaged mattresses and the effectiveness of antimicrobial coatings, researchers continue to uncover persistent risks in environmental hygiene, highlighting the critical need for innovative, continuous disinfection strategies in health care settings.
Beyond the Surface: Rethinking Environmental Hygiene Validation at Exchange25
June 30th 2025Environmental hygiene is about more than just shiny surfaces. At Exchange25, infection prevention experts urged the field to look deeper, rethink blame, and validate cleaning efforts across the entire care environment, not just EVS tasks.
A Controversial Reboot: New Vaccine Panel Faces Scrutiny, Support, and Sharp Divides
June 26th 2025As the newly appointed Advisory Committee on Immunization Practices (ACIP) met for the first time under sweeping changes by HHS Secretary Robert F. Kennedy Jr, the national spotlight turned to the panel’s legitimacy, vaccine guidance, and whether science or ideology would steer public health policy in a polarized era.