Posted October 1, 2010
Diagnostic laboratories could screen solid media plates for Campylobacter colonies within 24 hours, using a combination of conventional imaging and spectroscopy, according to the Department of Agriculture.
Seung-Chul Yoon, PhD, a research electronics engineer with the USDA Agricultural Research Service, has led a study on the use of hyperspectral imaging in detecting Campylobacter. He said the technology can be used to gather spatial information, find spectral signatures of target organisms on the basis of their chemical composition, and differentiate between Campylobacter and other bacteria that are commonly found in poultry carcasses and also grow on solid media. The studies have, so far, involved pure cultures of Campylobacter and frequently encountered non-Campylobacter bacteria.
"The next step is to use mixtures of pure cultures, and if we are successful again, then we will use food samples and chicken carcass rinses," he said.
Dr. Yoon said current cultural methods of detecting Campylobacter typically take 48 to 96 hours because of the need for enrichment, incubation, and testing of samples. He expects that hyperspectral imaging could also be applied to other bacteria, such as Salmonella and Escherichia coli.
Studies involving E coli O157 strains have yielded promising results, he said.
Researchers using the technique were unable to differentiate between Campylobacter species, Dr. Yoon said. But he expects the process could be used by laboratories that receive large numbers of samples from food products and need to test those samples for foodborne pathogens before the products can be sold to consumers.
Used in combination with an automated imaging technique, Dr. Yoon said the process could shorten testing times and increase accuracy of tests.