New York, Dec 27 (IANS): Pathogens, like salmonella, can survive for at least six months in cookies and sandwich crackers, new research has found.

The recent study was prompted by an increased number of outbreak of foodborne diseases linked to dry foods, said the researchers who wanted to see just how long bacteria that cause foodborne illness can survive in certain foods.

"There have been an increased number of outbreaks of diseases associated with consumption of contaminated dry foods. We would not expect salmonella to grow in foods that have a very dry environment," said lead researcher Larry Beuchat from University of Georgia in the US.

The researchers found that not only can harmful bacteria survive in dry foods, like cookie and cracker sandwiches, but they can also live for long periods of time.

For the study, researchers used five different serotypes of salmonella that had been isolated from foods involved in previous foodborne outbreaks.

"Isolates were from foods with very low moisture content," Beuchat said.

Focusing on cookie and cracker sandwiches, the researchers put the salmonella into four types of fillings found in cookies or crackers and placed them into storage.

The researchers used cheese and peanut butter fillings for the cracker sandwiches and chocolate and vanilla fillings for the cookie sandwiches.

These "are the kind that we find in grocery stores or vending machines", Beuchat said.

After storing, the scientists determined how long salmonella was able to survive in each filling.

In some cases, the pathogen was able to survive for at least to six months in the sandwiches, the findings showed.

"That was not expected," Beuchat said.

The study was published in the Journal of Food Protection.