Showing posts with label e-coli. Show all posts
Showing posts with label e-coli. Show all posts

Thursday, February 23, 2012

E.Coli: UCLA Engineers create cell phone-based sensor

Researchers from the UCLA Henry Samueli School of Engineering and Applied Science have developed a new cell phone–based fluorescent imaging and sensing platform that can detect the presence of the bacterium Escherichia coli in food and water.

The engineers combined antibody functionalized glass capillaries with quantum dots (semiconductors often used for medical imaging) as signal reporters to specifically detect E. coli particles in liquid samples using a lightweight, compact attachment to an existing cell-phone camera.

The cost-effective cell-phone attachment acts as a florescent microscope, quantifying the emitted light from each capillary after the specific capture of E. coli particles within a sample.

By quantifying the florescent light emission from each tube, the concentration of E. coli in the sample can be determined.

E. coli can easily contaminate food and drinking water. It poses a significant threat to public health, even in highly developed parts of the world, and causes a large number of hospitalizations and deaths every year.

As few as 10–100 E. coli particles can kill the cells of the intestinal lining, destroy the kidneys and cause blood clots in the brain, as well as seizures, paralysis and respiratory failure.

This study illustrates the promising potential of a cell phone–enabled, field-portable and cost-effective E. coli detection platform for the screening of both water and food samples.

Authors of the research include UCLA electrical engineering postdoctoral scholar Hongying Zhu; UCLA electrical engineering undergraduate student Uzair Sikora; and UCLA associate professor of electrical engineering and bioengineering Aydogan Ozcan. Ozcan is also a member of the California NanoSystems Institute at UCLA.

More information: The research is published in the peer-reviewed journal The Royal Society of Chemistry and is available online at RSC Publishing

Wednesday, June 1, 2011

Mid-outbreak, treatment found for deadly E. coli infections



An unusually lethal strain of the bacterium Escherichia coli has infected more than 1,500 in Germany, killing at least 16 people.

The current outbreak – traced back to contaminated fruits and vegetables – is caused by a rare E. coli strain called O104:H4. And scientists are at a loss to explain why it’s so virulent, and particularly in healthy young adult women.

In an attempt to avert anticipated deaths, doctors in the cities where the outbreak is centered have set up a spontaneous clinical trial for an experimental drug called eculizumab – sold as Soliris – recently listed as the world’s single most expensive drug.

While most E. coli strains are harmless, a distressingly high proportion of those infected with this this enterohemorrhagic E. coli (EHEC) suffer from hemolytic uremic syndrome (HUS) infection – a potentially lethal complication attacking the kidneys that can provoke comas, seizures, and stroke.

On Friday, Rolf Stahl of the Hamburg-Eppendorf University Hospital and Reinhard Brunkhorst of the German Society of Nephrology rolled out an emergency eculizumab treatment strategy to hospitals across the country.

The monoclonal antibody drug has been on the market since 2007 as a treatment for a rare immune system disorder paroxysmal nocturnal hemoglobinuria, which destroys red blood cells. A year’s treatment costs $409,500.

But just last week, a new study reported successful use of the drug in treating HUS. A toxin produced by EHEC activates ‘complement’ proteins, but overactivity can lead to tissue damage in the kidneys.

The team, led by Franz Schaefer of the Center for Pediatrics and Adolescent Medicine in Heidelberg, treated 3 EHEC-infected children with eculizumab – which blocked the complement proteins and improved the patients’ blood-cell counts and kidney function.

A few days after the paper was accepted for publication, HUS cases started appearing in northern Germany.

The drug’s manufacturer, Alexion, is now providing eculizumab free of charge in Germany, taking advantage of an unexpectedly large cohort of patients that might help to speed the drug’s approval for the treatment of HUS.

The drug costs at least €15,000 ($22,000) per patient.

“But we don’t want to be overly optimistic,” Brunkhorst cautions, “we have very little experience with this drug and don’t know how effective it will be.” And because this strain has never been implicated in an outbreak of human EHEC infections before, scientists are racing to sequence the strain’s DNA while doctors are figuring out how to save lives on the fly.

The Food and Drug Administration will conduct a 6-month ‘priority review’ of Soliris as a treatment for HUS. The agency usually takes 10 months to review drug candidates, but speeds up the process for conditions that don’t have good treatment options.

The study was published in the New England Journal of Medicine last week.

Saturday, December 12, 2009

Tomatoes, Leafy Green Leaves and Foodpoisoning

Leafy Greens

Leafy Greens

Leafy greens, eggs, and tuna are healthy for you right? That may be true, but these foods have also made the top of a list of the 10 riskiest foods regulated by the Food and Drug Administration, according to a new report by the Center for Science in the Public Interest (CSPI). In fact, those and seven other foods account for nearly 40 percent of all foodborne outbreaks linked to FDA-regulated food since 1990. CSPI identified 363 outbreaks linked to iceberg lettuce, romaine, spinach, and other leafy greens, variously contaminated with E. coli, norovirus, or salmonella, which caused 13,568 cases of illness. Manure, contaminated irrigation water, or poor handling practices are all possible culprits in those outbreaks.


Tomatoes

Tomatoes

In 2005 and 2006, tomatoes were implicated in four multistate outbreaks of salmonella, sickening hundreds of people. So it's really no surprise this salad staple made the list. The CSPI found tomatoes were involved in 31 outbreaks involving 3,292 reported cases of people falling ill.