Scientists at the US Food and Drug Administration (FDA) have identified a harmless bacterial species that may help to reduce the risk of Salmonella contamination in commercially grown tomatoes by inhibiting growth of the pathogen.
The bacterium, identified as a strain of Paenibacillus alvei, was isolated epiphytically from plants native to the Virginia Eastern Shore tomato growing region. Strain TS-15 showed a broad spectrum of antimicrobial activity against a number of important foodborne pathogens and bacterial plant pathogens. When it was used to challenge cells of Salmonella Newport on the fruits, leaves and flowers of tomato plants, the number of S. Newport cells on the plants fell significantly and 90% had no detectable Salmonella on the flowers by day five.
The FDA researchers conclude that the bacterium is a highly effective antagonist for Salmonella Newport on whole tomato plants and could help to reduce the risk of contamination during tomato production. They screened a wide range of bacteria for their ability to inhibit or destroy Salmonella, but only strain TS-15 was both effective and harmless to humans. “This bacterium has no known history of human pathology, making it a great candidate as a biological control agent,” said study author Jie Zheng.
The study will be published in the journal Applied and Environmental Microbiology, but a draft manuscript can be found in full here.