Nine people have been hospitalised with salmonella linked to three Angkor Bakery stores in Adelaide's northern suburbs.
Deputy Chief Medical Officer Nicola Spurrier says there have been 11 confirmed cases in people who ate Vietnamese rolls from the three outlets.
"Early investigations indicate the cases could be linked to raw egg, butter, pate or BBQ pork ingredients," Dr Spurrier said.
"Food and environmental samples have been collected from all stores and results will assist in identifying the source of the contamination."
The Angkor bakeries have agreed to stop selling Vietnamese rolls until the source has been confirmed.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
The company's cleaning and sanitising procedures have also been assessed and improved and will continue to be monitored.
Dr Spurrier said people could experience symptoms of salmonella infection between six and 72 hours after exposure and they usually last for three to seven days.
Symptoms include fever, diarrhoea, vomiting, headaches, stomach cramps and loss of appetite.
More severe symptoms may occur in young children, older people, pregnant women and people who have compromised immune systems.
