New device to detect food pathogens

A system that concentrates foodborne salmonella and other pathogens faster than conventional methods has been developed. The device uses hollow thread-like fibers that filter out the cells, leading to faster detection.

The device is called a continuous cell concentration device. The device, if modeled commercially, will allow food or water samples to be analyzed in order to screen for pathogens. Foodborne pathogens can seriously affect anyone, but for pregnant women and their babies, certain pathogens can be particularly harmful, even fatal. An example are the bacteria Salmonella.

The device is said to be fast enough to produce a result within a single work shift at food processing plants. At present, many samples do not produce results for several days, meaning that many food processes continue ‘at risk’.

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.

In test runs, 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 pre-treated 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 device was invented by scientists at Purdue University, led by Professor Michael Ladisch. The findings have been published in the journal Applied and Environmental Microbiology. The paper it titled “Rapid Sample Processing for Foodborne Pathogen Detection via Crossflow Microfiltration.”

Posted by Tim Sandle