( Cornell University scientists have deve...)New technique rapidly detects illness-causing bacteria

The presentation by Sam Nugen, a graduate student in Cornell's food science department, will focus on detecting the food-borne bacteria Streptococcus pyogenes (S. pyogenes ), but the technique can be applied to a wide variety of bacterial pathogens, including Escherichia coli (E. coli ).

The new biosensor works in a test tube and a positive result shows up as a red line on a strip, much like a pregnancy test. Newly designed software gives researchers a powerful tool for increasing the sensitivity of the analysis.

The method may help researchers and companies that are in the business of tracking food-borne pathogens, allowing technicians to determine a source quickly. It may also help to analyze a throat culture swab, to tell if someone has an illness like strep throat.

"We hope to see this technique commercialized, because it is very rapid compared to all the standard methods right now," said Nugen, the study's lead author. Nugen conducted his research in the laboratory of Antje Baeumner, Cornell associate professor of biological and environmental engineering, who is also a co-author of the study.

"It would be great if we came up with something that became a standard," Nugen added.

Current biosensors rely on a time-consuming technique called gene amplification that requires costly equipment: Technicians take a piece of DNA from a sample and add enzymes that make many copies of the DNA. Duplicating or "amplifying" the DNA makes a pathogen easier to detect.

The new process starts with genetic material that is extracted from a food sample. This material, called ribosomal RNA (rRNA), is responsible for translating genetic information c
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Source:Cornell University News Service