Bruce Applegate, an associate professor of food science at Purdue University, has developed what he describes as a faster and less expensive way to test for E. coli.
Ideally, the technology will eventually allow for more testing, ostensibly leading to better overall food safety.
“The lower the cost, the more tests you can do,” Applegate said.
He and his fellow researchers have engineered a virus called NanoLuc that infects E. coli O157:H7 and causes it to glow in the dark.
Traditionally, samples are tested for E. coli after an enrichment process allows the number of bacteria — if present — to grow to a detectable level. The virus created by Applegate and his group can detect the bacteria during the enrichment process.
“Once the enrichment was done, you could actually look then (to see whether E. coli was present) as opposed to doing the test afterwards,” Applegate said.
Purdue owns the technology, as Applegate and his co-inventors created it while working for the university, but Purdue has leased it to Applegate so he can develop it further at his startup Phicrobe. The company received $20,000 from the Elevate Purdue Foundry Fund, which supports startups affiliated with the university.
“Our current president of the university, Mitch Daniels, has really been proactive with some of the people that he’s hired at the Purdue Research Foundation and the Office of Technology Commercialization to really push these kind of efforts, and to get these things out to benefit the public and to generate jobs as well,” Applegate said.
The company is currently working to get the technology certified by the Association of Official Analytical Chemists, which should happen in the next year.
“What we’re looking for is partners, people who already sell detection kits, so we just produce the reagents,” Applegate said. “We have some people already interested where we can actually marry our technology up to a technology that’s already available.”
Another benefit of the technology Applegate and his fellow researchers have developed is that it quantifies bacteria in addition to simply recognizing their presence. That information can help those testing better understand the amount of risk.
“If you want to know if there’s a contamination on a surface or in a drain, you want to know whether there’s one there or there’s 10,000 there, because one’s a problem, but 10,000 is a huge problem,” Applegate said. “Right now a lot of the techniques, they just do … plus-minus.”
The technology should also decrease the likelihood of a false positive.
“These assays will only detect live bacteria,” Applegate said. “With some of the DNA tests, you don’t know whether it’s alive or not. You just know the DNA is there. So if it’s been processed in some way and killed, then it would still come back as a positive.”
Funding and support for the study came from the U.S. Department of Agriculture, the Purdue Research Foundation Fellowship and the National Council for Science and Technology of Mexico, according to a news release.