How Do Fresh Veggies and Fruits Get ‘Poisoned’? Indian Scientists Crack the Mystery
Photo Source: Magpixel

How Do Fresh Veggies and Fruits Get ‘Poisoned’? Indian Scientists Crack the Mystery

Contamination of vegetables by E.coli and Salmonella bacteria are the most common causes of food poisoning. But how this happened was unknown – Till now!


Contamination of salad vegetables by E.coli and Salmonella bacteria are the most common causes of food poisoning. Although most Salmonella outbreaks are linked to contamination during handling and transportation of the vegetables, there are also cases where the infectious bacterium had entered the plant when it was still in the farmland.

Photo Source: Indian Photography/Facebook

How does it enter the plant? So far, the mechanism was not known. A new study by researchers at the Indian Institute of Science (IISc) and the University of Agricultural Sciences (UAS), Bengaluru, has solved the mystery.

They have found that unlike other disease-causing bacteria that enter the root, fruit or leaf by producing enzymes to break down the plant’s cell wall, Salmonella sneaks in through a tiny gap created when a lateral root branches out from the plant’s primary root.

The researchers were studying how different types of bacteria colonize the roots of tomato plants. While other bacteria were spread across the root, Salmonella clustered almost exclusively around areas where lateral roots emerge. When a lateral root pierces open the wall of the primary root to spread across the soil, it leaves behind a tiny opening. They figured out that it was entering through the gap with the help of fluorescent tagging and imaging.

They also noticed that under same conditions a plant with a greater number of lateral roots harbored a greater concentration of Salmonella than one with fewer lateral roots. Similarly, when plants were artificially induced to produce more lateral roots, Salmonella concentration increased.

Photo Source: Magpixel

Tomatoes plucked from these plants also tested positive for Salmonella infection, revealing its ability to travel all the way up to the fruit. “It is just like a systemic infection in humans,” said senior author Dipshikha Chakravortty, Professor, Department of Microbiology and Cell Biology, IISc. The researchers have published a paper on their work in journal, BMC Plant Biology.

Kapudeep Karmakar, PhD student in the Department of Microbiology and Cell Biology, IISc, and first author of the paper, noted that there are several possible sources from where Salmonella can reach the soil, such as manure containing animal feces or contaminated irrigation water. “Various studies show that irrigation water gets contaminated by sewage water. When that irrigation water is applied in the field, the soil becomes the portal for Salmonella to enter,” he said.

Photo Source: Pixabay

Environmental factors, he said, also appear to aid its infiltration. For, they found that when salt concentration in the soil increases, plants produce more lateral roots and therefore become more vulnerable to Salmonella infection.

In follow-up studies, the researchers plan to look at Salmonella infiltration in other edible vegetables and work on strategies to detect and prevent soil contamination. “If the soil is contaminated, there has to be a mechanism to either decontaminate it or use some antidotes like bio-fertilizers that can out-compete the pathogenic bacteria,” said Dr. Chakravortty.

Salmonella is increasingly becoming a notorious pathogen. It can cause a diverse range of infections in diverse hosts, from birds to reptiles, poultry and livestock. Mortality is high because of its able to cross the blood-brain barrier.

Article courtesy: India Science Wire.

You May Also Like: Indian Scientists Reveal How Cells of ‘Wonder Leaf’ Neem Produce Useful Chemicals!

Support the voice of unsung heroes and extra-ordinary citizens

We believe that It is essential for a country like ours to have a voice that celebrates unsung heroes, gives a platform for change makers, inspires millions of people. By using the power of constructive journalism, we want to change India – one story at a time.

While we do have advertising revenues, they aren’t enough to cover the costs of bringing all these stories to you. So, if you believe in us and a better India, and want this positive news movement to grow, then do consider supporting us via the above buttons.

Have questions? Do read our FAQs

Like this story? Or have something to share?
Write to us:
Connect with us on Facebook and Twitter.

Let’s be friends :)
Sign in to get free benefits
  • Get positive news daily on email
  • Join our community of positive ambassadors
  • Become a part of the positive movement
Thank you for your support.
Please fill the following details to proceed.