Salmonella Evolves: New Dangerous Strains Pose Increased Risk for Food Producers, Manufacturers, and the Patrons Who Consume The Food They Produce
Scientists at the University of Delaware have found new strains of Salmonella that are not able to be washed off of infected plants, such as leafy greens and other vegetables. By entering through a plants stomates, the microscopic holes in plant’s leafs that open and close during the gas exchange process, the Salmonella bacteria evades the plants immune system response and is able to freely infect the plant. Typically, plant bacteria and fungi infect plants because they have the enzyme necessary to open closed stomates. Salmonella is a bacterial disease that typically infects humans, not plants, and does not have the enzyme necessary to open stomates. Salmonella usually only infects plants topically duringgrowing and harvesting, often occurring during the picking and transportation process from farms to stores. Most times the contamination of these fruits and vegetables is through direct contact with infected feces or water infected with feces. Because the Salmonella is only on the plant’s surface, the surface level infection can be removed by washing plants with soap and water, effectively ejecting the Salmonella bacteria from the plant and making it safe to eat
The new danger identified by the scientists at the University of Delaware shows these new strains of Salmonella are able to suppress the immune response of plants and enter the stomates. This new method of infection allows Salmonella to infect plants internally, making it impossible to simply “wash off” the Salmonella bacteria. Because Salmonella is a foodborne illness causing bacteria in humans, scientists are increasingly concerned with signs that Salmonella has successfully jumped “kingdoms” and acquired new infection mechanisms.
Scientists are currently attempting to discover whether the Salmonella bacteria is now using the plant it infects as a host, as it does in humans. If so, this will demonstrate a very dangerous trend in food borne illness.
According to the CDC, Salmonella causes approximately 1.35 million infections, 26,500 hospitalizations, and 420 deaths every year. While already struggling to decrease the amount of Salmonella infections in the United States, these new strains warrant new methods to both detect and destroy Salmonella bacteria before it enters the general public.
https://www.frontiersin.org/articles/10.3389/fmicb.2020.00500/full#B45
