Salmonella's Tolerance to Desiccation
Low moisture foods do not allow the growth of microorganisms and have traditionally been considered safe from contamination from pathogens such as Salmonella. However, recent outbreaks of salmonellosis linked to low water content foods such as chocolate, dried milk, almonds, peanut butter, peanut products, toasted oats cereal and dried spices, have demonstrated that this bacterium survives dry conditions very well. Furthermore, Salmonella cells subjected to dry conditions can even became more heat tolerant. This response has clear implications for food processing when heating is used to kill foodborne pathogens making Salmonella an important emerging problem for this food sector. Findings by food scientists in the UGA Center for Food Safety suggested that two genes that have been previously known to be involved in its pathogenicity are required for Salmonella's survival during desiccation. The elucidation of the genetic components of Salmonella's unique ability to remain alive and infectious in dry foods will be critical to find intervention strategies and prevent further diseases. In addition, the understanding that further reduction in water content increases its resistance to heating will help food processors to design processing steps that will advance the control of food contamination and protection of the consumer.