Machine speeds concentration step in food-pathogen detection

Researchers have developed a system that concentrates foodborne salmonella and other pathogens faster than conventional methods by using hollow thread-like fibers that filter out the cells, representing a potential new tool for speedier detection. The machine, called a continuous cell…

Researchers have developed a system that concentrates foodborne salmonella and other pathogens faster than conventional methods by using hollow thread-like fibers that filter out the cells, representing a potential new tool for speedier detection.

The machine, called a continuous cell concentration device, could make it possible to routinely analyze food or water samples to screen for pathogens within a single work shift at food processing plants.

“This approach begins to address the critical need for the food industry for detecting food pathogens within six hours or less,” said Michael Ladisch, a distinguished professor of agricultural and biological engineering at Purdue University. “Ideally, you want to detect foodborne pathogens in one work shift, from start to finish, which means extracting the sample, concentrating the cells and detection.”

A report from the Centers for Disease Control and Prevention (CDC) indicates a lack of recent progress in reducing foodborne infections and highlights the need for improved prevention. Although many foodborne illnesses have declined in the past 15 years, the number of laboratory-confirmed salmonella cases did not change significantly in 2012 compared with 2006 to 2008.

The first step in detecting foodborne pathogens is concentrating the number of cells in test samples. The new system enables researchers to carry out the concentration step within one hour, compared to a day for the standard method now in commercial use, said Ladisch, also a professor of biomedical engineering and director of Purdue’s Laboratory of Renewable Resources Engineering (LORRE)

Findings are detailed in a research paper to appear in November in the journal Applied and Environmental Microbiology.

The paper was authored by doctoral student Xuan Li; LORRE research scientist Eduardo Ximenes; postdoctoral research associate Mary Anne Roshni Amalaradjou; undergraduate student Hunter B. Vibbert; senior research engineer Kirk Foster; engineering resources manager Jim Jones; microbiologist Xingya Liu; Arun K. Bhunia, a professor of food microbiology; and Ladisch.

Findings showed the system was able to concentrate inoculated salmonella by 500 to 1,000 times the original concentration in test samples. This level of concentration is required for accurate detection. Another finding showed the system recovered 70 percent of the living pathogen cells in samples, Ladisch said.

“This is important because if you filter microorganisms and kill them in the process that’s self-defeating,” he said. “The goal is to find out how many living microorganisms are present.”

The machine was used to concentrate cells in a sample of chicken meat. The sample is first broken down into the consistency of a milkshake and chemically pretreated to prevent the filtering membranes from clogging. The fluid is then passed through 12 hollow-fiber filters about 300 microns in diameter that are contained in a tube about the size of a cocktail straw. The filtering process continues until pathogens if present are concentrated enough to be detected.

The technique, developed by researchers from Purdue’s colleges of Engineering and Agriculture, could be performed during food processing or vegetable washing before the products are shipped.

The U.S. Department of Agriculture will test the system, which is not yet ready for commercialization.

One feature that could make the machine practical for commercial application is that it can be quickly cleaned between uses. The tubes are flushed with sodium hydroxide and alcohol.

Purdue has filed a patent application for the concept.
Article adapted by Medical News Today from original press release. Click ‘references’ tab above for source.
Visit our infectious diseases / bacteria / viruses section for the latest news on this subject.

The research is funded by the U.S. Department of Agriculture, Purdue’s Agricultural Research Programs and Center for Food Safety Engineering, and the Department of Agricultural and Biological Engineering.

Rapid Sample Processing for Foodborne Pathogen Detection via Crossflow Microfiltration. Published ahead of print 6 September 2013, doi: 10.1128/AEM.02587-13 AEM.02587-13

Purdue University

Please use one of the following formats to cite this article in your essay, paper or report:MLA
University, Purdue. “Machine speeds concentration step in food-pathogen detection.” Medical News Today. MediLexicon, Intl., 16 Oct. 2013. Web.17 Oct. 2013. <http://www.medicalnewstoday.com/releases/267483.php>

APA
University, P. (2013, October 16). “Machine speeds concentration step in food-pathogen detection.” Medical News Today. Retrieved fromhttp://www.medicalnewstoday.com/releases/267483.php.

Please note: If no author information is provided, the source is cited instead.

Rate article:
(Hover over the stars then click to rate)

Patient / Public:or

Health Professional:

Add Your Opinion On This Article‘Machine speeds concentration step in food-pathogen detection’Please note that we publish your name, but we do not publish your email address. It is only used to let
you know when your message is published. We do not use it for any other purpose. Please see our privacy policy for more information.
If you write about specific medications or operations, please do not name health care professionals by name.
All opinions are moderated before being included (to stop spam). We reserve the right to amend opinions where we deem necessary.

Contact Our News Editors

For any corrections of factual information, or to contact the editors please use our feedback form.
Please send any medical news or health news press releases to:

Note: Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care
professional. For more information, please read our terms and conditions.