finds its way into a food-processing plant, the bacteria can be extremely hard
to eliminate, a new study finds.
Researchers used three types of disinfectants to try to kill a build-up of
salmonella bacteria – known as a bio film – that had formed on a variety of
hard surfaces. The study was published online and in the February print issue
of the journal Applied and Environmental Microbiology.
"We found that it was not possible to kill the salmonella cells using
any of the three disinfectants if the bio film was allowed to grow for seven
days before the disinfectant was applied," researcher Mary Corcoran, of
National University Ireland, said in a journal news release.
The bio films survived even after the researchers soaked them in
disinfectant for 90 minutes.
"We found that all of the types of salmonella we looked at were able to
adopt the specialised bio film lifestyle on all of the surfaces we looked at,
including glass, stainless steel, glazed tile and plastic," Corcoran said.
"The bio film of salmonella gets denser over time, and becomes more firmly
attached to the surface."
Further research needed
Corcoran said the findings show that food-processing facilities must keep
salmonella out of clean areas where cooked foods are further processed and
"People need to question whether disinfectants that are promoted as
killing various types of bacteria are really as effective in real-life
situations where bio films can form as they are claimed to be based on
experiments that do not use bio films," she said. "A lot of the time,
the disinfectant may add very little, if anything, to good cleaning and
appropriate food-handling practices."
Further research is needed to find better ways to kill salmonella bio films,
Each year in the United States, there are more than 1 million cases of
salmonella infection that result in 23 000 hospitalisations and 450 deaths,
according to the US Centers for Disease Control and Prevention.
scientist use salmonella bug to kill cancer cells
cutting boards are germ traps(Picture: Salmonella bacteria from Shutterstock)