Virginia Tech scientists have provided new evidence that biofilms bacteria that adhere to surfaces and build protective coatings are at work in the survival of the human pathogen Salmonella.
Monica Ponder processes peanut butter through a simulated gastrointestinal system. Courtesy of Virginia Tech.
Â
Virginia Tech scientists have provided new evidence that biofilms bacteria that adhere to surfaces and build protective coatings are at work in the survival of the human pathogen Salmonella.
One out of every six Americans becomes ill from eating contaminated food each year, with over a million illnesses caused by Salmonella bacteria, according to the Centers for Disease Control and Prevention. Finding out what makes Salmonella resistant to antibacterial measures could help curb outbreaks.
Researchers affiliated with the Fralin Life Science Institute discovered that in addition to protecting Salmonella from heat-processing and sanitizers such as bleach, biofilms preserve the bacteria in extremely dry conditions, and again when the bacteria are subjected to normal digestive processes. The study is now online in the International Journal of Food Microbiology and will appear in the April issue.
Biofilms are an increasing problem in food processing plants serving as a potential source of contamination, says Monica Ponder, an assistant professor of food science and technology in the College of Agriculture and Life Sciences. We have discovered that Salmonella in biofilms survive on dried foods much better than previously thought, and because of this are more likely to cause disease, said Ponder.
Outbreaks of Salmonella associated with dried foods such as nuts, cereals, spices, powdered milk and pet foods have been associated with over 900 illnesses in the last five years. These foods were previously thought to be safe because the dry nature of the product stops microbial growth.
Most people expect to find Salmonella on raw meats but don't consider that it can survive on fruits, vegetables or dry products, which are not always cooked, says Ponder.
In moist conditions, Salmonella thrive and reproduce abundantly. If thrust into a dry environment, they cease to reproduce, but turn on genes which produce a biofilm, protecting them from the detrimental environment.Â
Researchers tested the resilience of the Salmonella biofilm by drying it and storing it in dry milk powder for up to 30 days. At various points it was tested in a simulated gastrointestinal system. Salmonella survived this long- term storage in large numbers but the biofilm Salmonella were more resilient than the free-floating cells treated to the same conditions.
The bacterias stress response to the dry conditions also made it more likely to cause disease. Biofilms allowed the Salmonella to survive the harsh, acidic environment of the stomach, increasing its chances of reaching the intestines, where infection results in the symptoms associated with food poisoning.
This research may help shape Food and Drug Administrations regulations by highlighting the need for better sanitation and new strategies to reduce biofilm formation on equipment, thus hopefully decreasing the likelihood of another outbreak.
Source: Virginia Tech
Hiding in Plain Sight: The Most Harmful and Costly Hospital-Acquired Infection
February 5th 2025Nonventilator hospital-acquired pneumonia (NV-HAP) is a deadly, overlooked infection impacting patient outcomes. With new diagnostic tools and prevention strategies, hospitals must prioritize oral hygiene to reduce risk.
The Key to Sterile Processing Success: Leadership Engagement and Team Collaboration
January 24th 2025Effective sterile processing leadership requires active engagement, clear communication, and a transformational approach to foster collaboration, accountability, and quality in infection prevention and surgical instrument management.
Top 7 Infection Control Today Articles of 2024: Insights and Innovations
December 30th 2024From advanced sterilization methods to combating antimicrobial resistance, Infection Control Today’s top articles of 2024 delivered actionable strategies for safer healthcare environments and improved patient outcomes.
Redefining Competency: A Comprehensive Framework for Infection Preventionists
December 19th 2024Explore APIC’s groundbreaking framework for defining and documenting infection preventionist competency. Christine Zirges, DNP, ACNS-BC, CIC, FAPIC, shares insights on advancing professional growth, improving patient safety, and navigating regulatory challenges.
Tackling Health Care-Associated Infections: SHEA’s Bold 10-Year Research Plan to Save Lives
December 12th 2024Discover SHEA's visionary 10-year plan to reduce HAIs by advancing infection prevention strategies, understanding transmission, and improving diagnostic practices for better patient outcomes.
Environmental Hygiene: Air Pressure and Ventilation: Negative vs Positive Pressure
December 10th 2024Learn more about how effective air pressure regulation in health care facilities is crucial for controlling airborne pathogens like tuberculosis and COVID-19, ensuring a safer environment for all patients and staff.