Navigation Links
Light, photosynthesis help bacteria invade fresh produce

Exposure to light and possibly photosynthesis itself could be helping disease-causing bacteria to be internalized by lettuce leaves, making them impervious to washing, according to research published in the October issue of the journal Applied and Environmental Microbiology.

Salmonella enterica is a common cause of foodborne gastroenteritis, with an estimated number of 1 to 3 million human cases per year in the United States. Fresh produce is increasingly being implicated as a source of infection. One of the largest foodborne outbreaks in recent history, the Salmonella St. Paul outbreak in 2008 which sickened over 1,400 people, was associated with tomatoes and jalapeno peppers.

Previous studies of foodborne pathogens on produce have found that the bacteria do not only attach to the surface of fresh produce but find their way below the surface of the skin through pores called stomata where they can hide from and resist washing and food sanitizers.

In the study, researchers from the Agricultural Research Organization at the Volcani Center in Israel and Tel-Aviv University examined the role that light and photosynthesis might play on the ability of salmonella bacteria to infiltrate lettuce leaves via stomata. Sterile iceberg lettuce leaves were exposed to bacteria either in the light, in the dark, or in the dark after 30 minutes of exposure to light. Incubation in the light or preexposure to light resulted in aggregation of bacteria around open stomata and invasion into the inner leaf tissue. In contrast, incubation in the dark resulted in a scattered attachment pattern and very little internalization.

The researchers believe that the increased propensity for internalization in the light may be due to several factors. First, in the absence of light plants enter a period of dormancy, where stomata are closed and no photosynthesis takes place. In the light, the stomata are open. Additional findings also suggest that the bacteria are attracted to the open stomata by the nutrients produced during photosynthesis which are not present in the dark.

"The elucidation of the mechanism by which Salmonella invades intact leaves has important implications for both pre- and postharvest handling of lettuce and probably other leafy vegetables. The capacity to inhibit internalization should limit bacterial colonization to the phylloplane and consequently might enhance the effectiveness of surface sanitizers," say the researchers.


Contact: Jim Sliwa
American Society for Microbiology

Related biology news :

1. Research project aims to control sunlight, extend growing season and conserve energy
2. The sky is not falling: Pollution in eastern China cuts light, useful rainfall
3. Researchers successfully simulate photosynthesis and design a better leaf
4. Discovering the secret code behind photosynthesis
5. Pliable proteins keep photosynthesis on the light path
6. Shuttle brings space-grown strep bacteria back for study
7. The worlds oldest bacteria
8. Bacteria from sponges make new pharmaceuticals
9. Boston University biomedical engineers find chink in bacterias armor
10. University of Leicester scientists discover technique to help friendly bacteria
11. Spaceflight shown to alter ability of bacteria to cause disease
Post Your Comments:
(Date:6/22/2016)... 22, 2016  The American College of Medical Genetics and ... Magazine as one of the fastest-growing trade shows during ... the Bellagio in Las Vegas . ... of growth in each of the following categories: net square ... number of attendees. The 2015 ACMG Annual Meeting was ranked ...
(Date:6/21/2016)... Columbia , June 21, 2016 ... to the new role of principal product architect ... named the director of customer development. Both will ... chief technical officer. The moves reflect NuData,s strategic ... in response to high customer demand and customer ...
(Date:6/15/2016)... June 15, 2016 Transparency ... titled "Gesture Recognition Market by Application Market - Global Industry Analysis ... 2024". According to the report, the  global gesture recognition ... 2015 and is estimated to grow at a ... by 2024.  Increasing application of gesture ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... SAN DIEGO , June 27, 2016  Sequenom, ... company committed to enabling healthier lives through the development ... Supreme Court of the United States ... Federal courts that the claims of Sequenom,s U.S. Patent ... the patent eligibility criteria established by the Supreme Court,s ...
(Date:6/27/2016)... , June 27, 2016  Liquid Biotech ... announced the funding of a Sponsored Research Agreement ... circulating tumor cells (CTCs) from cancer patients.  The ... in CTC levels correlate with clinical outcomes in ... These data will then be employed to support ...
(Date:6/24/2016)... ... ... Researchers at the Universita Politecnica delle Marche in Ancona combed medical journal ... Their findings are the subject of a new article on the Surviving Mesothelioma website. ... the blood, lung fluid or tissue of mesothelioma patients that can help point doctors ...
(Date:6/23/2016)... SPRING, Md. , June 23, 2016 A ... collected from the crime scene to track the criminal down. ... and the U.S. Food and Drug Administration (FDA) uses DNA ... Sound far-fetched? It,s not. The ... genome sequencing to support investigations of foodborne illnesses. Put as ...
Breaking Biology Technology: