Scientific Posters

Rapid methods such as PCR have been making in-roads into the routine nutraceutical and dietary supplements testing, the potential of multiplex PCR for routine detection of multiple pathogens has yet to be ascertained. The diversity and ever-growing list of matrices in these industries further exacerbates the challenges for such methods and thereby the method compatibility should be reviewed with the adoption of new technology.

The use of traceable culture collection strains, including pathogenic ones, is necessary in food as well as water and environmental laboratories for various applications, including:

• Daily or regular Quality Control (QC) of methods, mandatory for accredited labs

• Performance testing of culture media and reagents

• Verification and in-house validation of methods (e.g., according to ISO 16140-3)

However, the use of (pathogenic) strains, which often require culture and inoculum preparations, can lead to cross-contamination of routine samples.

According to ISO/IEC 17025, testing laboratories should ensure they operate competently and are able to generate valid results. Implementation of Quality Control or Verification of methods requires the use of strains. Genetically Modified Microorganisms (GMM) (e.g., GFP tagged organisms) offer a less risky approach minimizing the impact of cross contamination events securing laboratory results.

Standard molecular methods (without immunoconcentration step) of STEC detection in food matrices based on stx and eae genes co-detection and Top5/7 serogroup associated genes may lead to identify a significant number of false positives without detection of all enterohemorrhagic Escherichia coli (EHEC) potentially present. These major limits may cause either a substantial economic loss for food industry and a food safety risk for consumers.

In the United States, the production and consumption of green leafy produce has been steadily rising. The most recent attribution estimates from Centers for Disease Control and Prevention (2013) indicated leafy produce to be responsible for the highest amount of foodborne illnesses and among the top five causes of foodborne hospitalizations and deaths. Between 1973 and 2012, Salmonella and Shiga toxinproducing Escherichia coli (STEC) species were the top bacterial pathogens responsible for outbreaks caused by leafy vegetables.

In order to meet the growing expectations of consumers and the vigilance of regulation authorities, the food industry now uses new technology to improve food traceability.

Standard molecular methods (without immunoconcentration step) of STEC detection in food matrices based on stx and eae genes co-detection and Top5/7 serogroup associated genes may lead to identify a significant number of false positives without detection of all enterohemorrhagic Escherichia coli (EHEC) potentially present. These major limits may cause either a substantial economic loss for food industry and a food safety risk for consumers.