Salmonella Strains Tables for Outbreak Related to Peanut Butter and Peanut Containing Products

The three tables below summarize the several different strains of Salmonella identified during the outbreak investigation related to peanut butter and peanut containing products in January, 2009. For more information on the PFGE process, see "How the PFGE Process Works".

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Table 1: The outbreak strain† of SalmonellaTyphimurium has been found in ill humans and in food samples during this outbreak investigation. These strains have been confirmed by CDC's PulseNet.

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†These bacteria are grouped as a single outbreak strain even thought they have slightly different DNA fingerprints (red rectangle). They are indistinguishable by all other laboratory tests, and they are part of the same outbreak. For example, Salmonella Typhimurium bacteria with these different patterns collected from sick people during the outbreak were indistinguishable by a different method used by PulseNet, called multi locus variable number tandem repeat analysis (MLVA). MLVA is a method used for the genetic analysis of particular microorganisms, such as bacteria like Salmonella. It is one of the new tools of forensic microbiology.

* standardized molecular subtyping (or “DNA fingerprinting”) of bacteria by pulsed-field gel electrophoresis (PFGE)

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Table 2: Salmonella strains of other serotypes than Typhimurium have been found in food and in environmental samples during this outbreak investigation. These strains have been confirmed by CDC's PulseNet (link to PulseNet) and are NOT associated with an increase in human Illness.

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Table 3: These Salmonella strains were reported by the company to have been isolated from the Peanut Corporation of America's Blakely, Georgia production plant. DNA fingerprinting (PFGE) results are not available for these strains. Salmonella serotype Anatum has not been associated with a recent increase in human illness. Because DNA fIngerprinting (PFGE) patterns are not available, we are unable to determine if the Typhimurium serotype is the outbreak strain or not, and if it is not, whether it is associated with an increase in human illness.

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* standardized molecular subtyping (or “DNA fingerprinting”) of bacteria by pulsed-field gel electrophoresis (PFGE)