Published by Communications and Public Affairs (519) 824-4120, Ext. 56982 or 53338
April 25, 2005
New E. coli Test Provides Better Results, Study Finds
A new detection method for E. coli-tainted foods has outstripped several of its competitors in effectiveness, according to a new study by a University of Guelph researcher.
Joseph Odumeru, from U of G’s Laboratory Services Division, has completed a year-long study evaluating a new method that rapidly tests for the presence of E. coli 0157:H7 bacteria — the most common E. coli strain related to food-borne illness in North America. He’s found the technique detected E. coli 0157:H7 100 per cent of the time in foods without false negative results.
The test also differentiates between non-toxic and toxic E. coli 94 per cent of the time, generating fewer false positives and enabling food safety personnel to work more quickly in recalling contaminated products. “The results were significant,” said Odumeru. “That means fewer false positives and faster recall times for contaminated food.”
Odumeru compared the effectiveness of this new bacterial detection kit, called Immunocard STAT! 0157:H7, to three other commercially available kits that food safety technicians use to detect low levels of E. coli 0157:H7 in food samples. In particular, he looked at how well each kit performed when probing food products that have been implicated in past E. coli 0157:H7 outbreaks, such as ground beef, unpasteurized apple cider, alfalfa sprouts and cheese.
Whenever food samples being tested contained the deadly bacteria, Immunocard STAT! 0157:H7 found it 100 per cent of the time. The kit also generated fewer false positive test results. Odumeru says false positives are a common error in many detection kits, and force scientists to retest food samples numerous times to ensure food safety. That’s expensive and takes up valuable time, which can mean more food-borne illness cases, he said.
“Our role as scientists is to develop better methods to detect bacteria and their toxins in common foods. We want to assist the Ontario food industry in being able to show that local foods are safe by testing with the best available methods," he said.
Next, Odumeru will determine Immunocard STAT! 0157:H7’s effectiveness in detecting E. coli 0157:H7 in drinking water. This research was sponsored by the Ontario Ministry of Agriculture and Food.