People infected with salmonella often suffer from fever, diarrhea, and abdominal cramps between 12 and 72 hours after infection. The illness often lasts between four and seven days and most people recover even without getting medical treatment.
Some Salmonella Serotypes May Cause DNA Damage
Findings of a new study conducted by food scientists from Cornell University, however, showed that some serotypes, or variations of salmonella species, may have permanent unwanted effects such that they can cause damage to the DNA.
For the new study, which was published in the journal mBio in December 2016, Cornell University researchers Rachel Miller and Martin Wiedmann looked at several serotypes of salmonella that encode for cytolethal distending toxin (S-CDT), a virulence component for the serotype responsible for typhoid fever.
The researchers found that four salmonella serotypes that commonly cause foodborne illness also carry the genetic material that encodes S-CDT. Although there are more than 2,500 salmonella serotypes, fewer than 100 are responsible for most of the foodborne illnesses.
With the aid of human cells grown in the laboratory, the researchers also found that the salmonella strains with S-CDT cause hallmark signatures that hint of DNA damage. The researchers explained that this ability to cause DNA damage may result in long-term health consequences.
"The more you expose your body's cells to DNA damage, the more DNA damage that needs to be repaired, and there may one day be a chance that the DNA damage is not correctly repaired. We don't really know right now the true permanent damage from these salmonella infections," Miller said.
Wiedmann said that damaged DNA from salmonella infection may result in a person suffering from long-term health consequences even after the infection subsides. An example of such long-term health impact is having longer bouts with foodborne illnesses.
"In this study, we demonstrate that at a cellular level, S-CDT significantly alters the outcome of infection by inducing DNA damage," the researchers wrote in their study. "Our data suggest that infection with salmonella strains that encode S-CDT has the potential to result in DNA damage, which may contribute to long-term sequelae."
Salmonella Infection Can Be Fatal
Figures from the U.S. Centers for Disease Control And Prevention show that about 1.2 million non-typhoidal salmonella illnesses and 450 deaths occur in the United States each year because of salmonella.
While most people who get infected with salmonella typically recover, there are individuals who are more vulnerable to the unwanted impacts of the illness. These include those who already have existing health conditions and weakened immune systems.
In 2015, an outbreak caused by salmonella-tainted cucumbers that were sold in the United States proved fatal. The second fatality of the outbreak, a woman from Texas, was already suffering from other serious illnesses prior to infection, but tests revealed that salmonella was a factor to her death.
Possible salmonella contamination often results in food recalls in the United States. Examples of products that have been recalled recently over salmonella fears include herbal teas, vitamin supplements, and macadamia nuts.