Using a combination of digital imaging and spectroscopy known as hyperspectral imaging, U.S. Department of Agriculture (USDA) scientists have found a way to distinguish Campylobacter from other microorganisms within 24 hours.
Hyperspectral imaging creates hundreds of individual wavelength measurements for each image pixel, capturing the unique “fingerprints” of microorganisms grown on solid media. “Campylobacter grows slowly, and usually you have to wait up to a 48-hour incubation time to identify it,” said lead author Seung-Chul Yoon, PhD, a research electronics engineer with the USDA’s Agricultural Research Service, which sponsored the study (Yoon SC, Lawrence KC, Line JE, et al. Sensing Instrum Food Quality Safety. 2010;4(1):35-49).
Differentiating Campylobacter from other organisms can be challenging because the different bacteria can look very similar. Dr. Yoon said, however, that his group “found that using hyperspectral imaging, almost 100% accuracy in distinguishing Campylobacter from other pathogens can be achieved within 24 hours incubation time.” Hyperspectral imaging may also be applicable to other pathogen detection studies, such as those working with Salmonella, he added.
The technology has some limitations. It cannot differentiate between strains of Campylobacter only between Campylobacter and other organisms. Dr. Yoon also noted that the research team has only studied hyperspectral imaging in pure organisms and not in mixed cultures. “We need to study the technique with naturally occurring organisms from food samples,” he said.