A study published in the journal mBio suggests that some of the Salmonella serotypes may damage a person’s DNA. There are more than 2,500 serotypes for Salmonella, but fewer than 100 serotypes cause most foodborne illness, according to the U.S. Centers for Disease Control and Prevention (CDC).
The researchers examined multiple serotypes of Salmonella that encode for cytolethal distending toxin, or S-CDT, a virulence component for serotype Typhi—the cause of typhoid fever. As it happens, the Salmonella serotypes called Javiana, Montevideo, Oranienburg, and Mississippi—common culprits in the foodborne illness world—also carry the genetic material that encodes S-CDT, the researchers found.
In human cells grown in the lab, Salmonella strains with S-CDT were also found to lead to hallmark signatures that indicate the presence of DNA damage. The ability to cause DNA damage may contribute to long-term disease consequences.
“Think about possible DNA damage this way: We apply sunscreen to keep the sun from damaging our skin. If you don’t apply sunscreen, you can get a sunburn—and possibly develop skin problems later in life,” said co-author Rachel Miller, a doctoral candidate in food science at Cornell. “While not the sun, Salmonella bacteria may work in a similar way. 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.”