Navigation Links
Light, photosynthesis help bacteria invade fresh produce
Date:9/28/2009

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
jsliwa@asmusa.org
202-942-9297
American Society for Microbiology
Source:Eurekalert

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:
*Name:
*Comment:
*Email:
(Date:3/22/2016)... PROVO and SANDY, ... Screening Ontario (NSO), which operates the highest sample volume ... testing, and Tute Genomics and UNIConnect, leaders in clinical ... today announced the launch of a project to establish ... testing panel. NSO has been contracted ...
(Date:3/15/2016)... JERUSALEM , March 15, 2016 ... Jerusalem , the technology-transfer company of the Hebrew University, ... developer of remote sensing technology of various human biological ... funding, raising $2.0 million from private investors. ... technology, based on the detection of electromagnetic emissions from ...
(Date:3/10/2016)... 2016 --> ... "Identity and Access Management Market by Component (Provisioning, Directory ... by Organization Size, by Deployment, by Vertical, and by ... The market is estimated to grow from USD 7.20 ... at a Compound Annual Growth Rate (CAGR) of 12.2% ...
Breaking Biology News(10 mins):
(Date:5/25/2016)... Melbourne, FL (PRWEB) , ... May 25, 2016 , ... ... of eight she tore her cruciate ligament in her left knee. Lady’s owner Hannah ... , a central Florida board-certified veterinary surgeon, to repair her cruciate ligament and help ...
(Date:5/24/2016)... ... 24, 2016 , ... Cell therapies for a range of ... research at Worcester Polytechnic Institute (WPI) that yielded a newly patented method of ... The novel method, developed by WPI faculty members Raymond Page, PhD, professor of ...
(Date:5/24/2016)... Jolla, CA (PRWEB) , ... May 24, 2016 , ... ... financial planning for corporate executives and entrepreneurs, held The Future of San Diego Life ... in the San Diego life science community attended the event with speakers Dr. Rich ...
(Date:5/23/2016)... ... ... for blood donations in South Texas and across the nation is growing. , But according ... donations are on the decline. In fact, donations across the country are at their lowest ... in the last four years alone. , There is no substitute for blood. , “We ...
Breaking Biology Technology: