A wide range of fresh produce has been linked to outbreaks of Escherichia coli and Salmonella enterica including melons, jalapeño and serrano peppers, basil, lettuce, horseradish sprouts and tomatoes. Researchers at Imperial College London are looking at how these bacterial pathogens latch onto fruits and vegetables and establish themselves in the first place.
This image shows the association of Escherichia coli with rocket leaves. Credit: Rob Shaw
They have discovered that strains of Salmonella behave differently when attached to ripe and unripe tomatoes. "Bacteria that attach to ripe tomatoes produce an extensive network of filaments, which is not seen when they attach to the surface of unripe tomatoes. This could affect how they are maintained on the surface," explained Professor Gad Frankel who is leading the research. "We are not completely sure yet why this happens; it might be due to the surface properties of the tomatoes or alternatively the expression of ripening hormones."
This is just one example of the subtle interplay between food-poisoning microbes and the fresh produce they contaminate, that determines how pathogens become established in the food chain. "Apart from Salmonella, strains of E. coli are also particularly devious in the way they interact with plant surfaces. They have hair-like appendages and flagella they can use as hooks to successfully secure themselves onto things like salad leaves."
Although fresh fruits and vegetables are recognized as important vehicles that transmit harmful bacteria, they are still important components of a healthy and balanced diet. "By and large, raw fruits and vegetables are safe to eat and provide numerous health benefits. By working out the reasons behind sporadic outbreaks of infections, we can control these better and help maintain consumer confidence. By improving food safety we would also see important economical and health benefits."
Understanding how bacteria interact with fresh produce is a crucial but only the first step, explained Professor Frankel. "Translating research into new policies or methods for decontamination is the challenge for future studies," he said.
Laura Udakis | EurekAlert!
Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences
Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences