Sunday, 20 November 2016

Rapid test for Salmonella in chicken developed

Microbiologists and technologists have joined forces to come up with a rapid and easy-to-use method to detect Salmonella in food such a chicken. The device contributes to contamination control.
Despite multiple warning about food storage and hygiene, foodborne diseases, like those derived from Salmonella bacteria, show little sign of going away. This means that safety and assurance are as reliant upon regular checks of food preparation establishments and food manufacturers as with good hygiene practices.
Salmonella is a Gram-negative rod shaped bacterium (the Gram-negative refers to the outcome of a cell staining test, relating to the structure of the organism’s cell wall).
To help on the detection front a new device has been developed at the University of Florida Institute of Food and Agricultural Sciences. The new method is a magnetic bead immunoassay. This is a diagnostic immunoassay that uses magnetic beads as labels in lieu of conventional enzymes. The assay involves the specific binding of an antibody to its antigen, where a magnetic label is conjugated to one element of the pair, with detection via a device called a magnetometer.
To test the device, scientists artificially contaminated food with Salmonella. These food samples were next tested using Salmonella-specific antibodies combined with a signal amplification technique. The test results showed Salmonella bacteria present after 15 hours.
The method therefore showed an accurate detection rate and the results were obtained far more quickly than with conventional cultural methods (which can take up to three days). This means an effective rapid microbiological method has been developed.
In a research note, the lead scientist Professor Soohyoun Ahn said: "The test has great potential as a simple monitoring system for foodborne pathogens in food samples, which can improve food safety and public health.”
Longer term it is hoped the method can be used to detect other potential food related pathogens like Escherichia coli.
The new device is described in the Journal of Food Safety. The associated research paper is titled “Magnetic Bead-Based Immunoassay Coupled with Tyramide Signal Amplification for Detection of Salmonella in Foods.”

Posted by Dr. Tim Sandle