Smaller, Stronger, Faster Labs

“It has a circulating system. You input all 250 mL of broth, and the first pass captures, say, 20% of microbes in suspension.” With a few more passes, a full pathogenic harvest has been reaped in less than an hour, he said.

The Pathatrix Auto system is a high volume immunomagnetic separation method for the rapid detection of a range of pathogens and spoilage organisms from a wide range of complex sample matrices.

Key to the success of this and related technologies is keeping them user friendly. “A long time ago, we asked people not to do microbiology unless they have a very good lab,” said Dr. Fung. The company encourages the food producer to send samples out for testing so as not to contaminate the facility. But the methods and machines have come a long way.

“I was just at a meeting where someone said that in the time it takes to prepare and send a sample by FedEx, the company can already have the data if it’s done in house.” These days, even a small company can afford the price and space for a small biological hood, and, often, that is all that is needed.

This has piqued both domestic and global interest. “There are many more workshops on rapid methods popping up right now,” said Dr. Fung, a leading speaker in the field, who was in Abu Dhabi last year and in Cancun in recent weeks. Next year, he plans to attend workshops in Hong Kong, Turkey, and Greece. “I’ve been going all over the place and doing workshops; the excitement is there.”

Mike Doyle, PhD, director of the Center for Food Safety at the University of Georgia, acknowledges the need for speed. “If we’re going to do finished product testing—and the signs of the time are saying we are or the outbreaks are going to be more killing—you’re going to have to have quick test, because it’s a test-and-hold situation.”

The shipment of that perishable product, wherever it may be, is waiting on the test results. Rapid testing is key. “The standard right now is 24 hours, and some say they can get it down to 12,” Dr. Doyle said. But the real need is testing in real time. “It’s where a product passes under a sensor and you have your answer. That’s where we need to go,” he said.

Dr. Doyle will serve as science advisor to Roka Bioscience, a recent spin-off from Gen-Probe in San Diego, Calif. “This detection technology will rely on 16S RNA, which gives you a whole lot more signal than you get with DNA-based assays.” An enrichment phase could be cut from 24 to four hours with this technology, he said.

Mocon is launching the OpTech O2 platinum, a new oxygen analyzer that uses optical fluorescence technology.

New Techniques in Contaminant Prevention

Dr. Doyle believes that the science/business world will continue to spearhead innovation in detection; however, new techniques for contaminant prevention are coming from academia. Dr. Doyle’s group, for example, just had a major breakthrough while working on an effective chemical treatment to inactivate pathogens such as Salmonella, Listeria, and E. coli without ruining the product. Because many compounds kill, “the hard part is to retain the quality characteristics, especially something sensitive like lettuce.”

Dr. Doyle’s new combination of levulinic acid and the detergent sodium dodecyl sulfate has not only been shown to have high activity, including on biofilms, but it has no negative impact on organic tissue, he said (J Food Prot. 2009;72(5):928-936).

Prevention also concerns Alan Shema, product manager for consulting and testing services at Mocon in Minneapolis. “We’ve seen growing interest in testing to understand the interaction between the packaging materials and the product:” specifically, gas permeability or residual oxygen. The presence of oxygen may change the flavor or aroma of a product and allow the growth of microbes.