Researchers from National University of Ireland, Galway conducted a study in which they attempted to kill Salmonella biofilms on a variety of hard surfaces, using three types of disinfectant.
This image shows photos of biofilms on surfaces at low magnification (300) and high magnification (3000) using electron microscope.
Credit: Photo courtesy of National University of Ireland, Galway
"We found that it was not possible to kill the Salmonella cells using any of the three disinfectants, if the biofilm was allowed to grow for seven days before the disinfectant was applied," says Mary Corcoran, a researcher on the study. Even soaking the biofilms in disinfectant for an hour and a half failed to kill them
The impetus for the study was a European outbreak in which 160 people in 10 countries became ill with gastroenteritis (vomiting and diarrhea) from the Agona serotype of Salmonella, says Corcoran. That outbreak was traced to meat from a major food-processing facility.
"It seems that Salmonella Agona entered into the environment in the part of the facility where meat that was already cooked was being handled, and it had survived and contaminated the cooked meat," says Corcoran. "We were interested in determining if this particular Salmonella, that caused the outbreak, might have something special about it that makes it better at surviving in the environment of a food processing facility. Was it better at forming a dense biofilm or was it more resistant to disinfectants than other Salmonella?"
The research uncovered nothing special about that specific strain.
"We found that all of the types of Salmonella we looked at were able to adopt the specialized biofilm lifestyle on all of the surfaces we looked at, including glass, stainless steel, glazed tile, and plastic, and that the biofilm of Salmonella gets more dense over time, and becomes more firmly attached to the surface," she says.
Corcoran warns that food processing facilities must take strict care to keep Salmonella out of the clean areas where cooked foods get further processing and packaged
"People need to question whether disinfectants that are promoted as killing various types of bacteria are really as effective in real life situations where biofilms can form as they are claimed to be based on experiments that do not use biofilms. A lot of the time, the disinfectant may add very little, if anything, to good cleaning and appropriate food handling practices," says Corcoran. "There is a need for more research to define better methods for killing Salmonella biofilms."
In the US, an estimated million-plus cases of Salmonella occur annually, with 23,000 hospitalizations and 450 fatalities reported each year, according to the Centers for Disease Control and Prevention.
A copy of the manuscript can be found online at http://bit.ly/asmtip0114e. The final version of the article is scheduled for the February 2014 issue of Applied and Environmental Microbiology.
Applied and Environmental Microbiology is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.
Jim Sliwa | EurekAlert!
Why do animals fight members of other species?
24.04.2015 | University of California - Los Angeles
Is a small artificially composed virus fragment the key to a Chikungunya vaccine?
24.04.2015 | Paul-Ehrlich-Institut - Bundesinstitut für Impfstoffe und biomedizinische Arzneimittel
KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.
Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...
A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...
Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits into place to encode data.
Unfortunately, the same drawbacks and perils of the mechanical sketch board have been just as pervasive in computing: making a change often requires starting...
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 24th. The measurements were performed with the LOFAR radio telescope located in the Netherlands.
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was...
Max Planck researcher Buhalqem Mamtimin determines how much nitrogen oxide is released into the atmosphere from agriculturally used oases.
In order to make statements about current and future air pollution, scientists use models which simulate the Earth’s atmosphere. A lot of information such as...
23.04.2015 | Event News
23.04.2015 | Event News
13.04.2015 | Event News
24.04.2015 | Materials Sciences
24.04.2015 | Materials Sciences
24.04.2015 | Health and Medicine