Detection in Food
The availability of new technologies has indeed greatly facilitated the genomic sequencing of this potentially lethal bacterium. Life Technologies has also developed a tool to test foods thought to be associated with the outbreak.
On June 6, shortly after reporting results from its sequencing efforts, the firm reported that it had completed development of a custom assay to detect the bacterium. Shipments of the TaqMan® E. coli O104 detection kit are now in Europe.
“A qPCR-based assay test is the most accurate method to detect harmful food-borne pathogens because a positive result indicates the presence of that particular strain’s DNA in the food sample that is being tested,” explained Nir Nimrodi, head of food safety at Life Technologies.
“It is also the fastest. While traditional laboratory testing methods can take up to 10 days for results, this test can determine the presence or absence of the European pathogen in 10 to 24 hours, depending on the sample type and size.”
It is hoped that the TaqMan E. coli O104 detection kits will provide an answer to the question that has received a variety of answers since the initial E. coli outbreak: Where did it come from? Originally, on May 26, health officials pointed to E. coli-contaminated cucumbers from Spain as culprits, but researchers later concluded that the cucumbers were contaminated with a different strain.
Suspicion then moved to bean sprouts but faded away after it was found that 23 of 40 samples from the suspect farm tested negative. As of June 8, focus had shifted back to cucumbers, as a CUCO (cucumber of unknown country origin) that had sickened a family in eastern Germany was found to be contaminated with the outbreak strain. The cucumber was discovered in the family’s compost, but there is no conclusive evidence that it’s the source.
Then on June 10, Reinhard Burger, president of the Robert Koch Institute, said that even though no tests of the sprouts from the suspect farm had come back positive for the E. coli strain behind the outbreak, an investigation into the pattern of the outbreak had produced enough evidence to indict the sprouts. German authorities said that they haven’t yet been able to resolve how sprouts at a farm became contaminated.
Along the search for clues about the source of the killer E. coli food bug, a restaurant in the northern German town of Luebeck and a festival in the northern city of Hamburg have also come under suspicion. The European Union has sent food safety experts to Germany to help authorities there identify the source of the deadly E. coli epidemic.
Stevenson noted that “a concern for the global healthcare industry is the ability to identify these pathogens as they arise and then be able to detect and screen for them rapidly and inexpensively.” Like with the Ion PGM, as novel pathogens continue to emerge, so will the need for similar disruptive but relatively affordable technologies.