Special Lunch Session 3 - May 20

When plant becomes foods: benefits and risks posed by the use of microbial control agents in edible plant production e.g. the case of Bacillus thuringiensis versus human pathogenic B. cereus.

Organisers: Mieke Uyttendaele (Dept. Food Technology, Safety & Health), Monica Höfte (Dept. of Plants & Crops), Ghent University, Belgium, member of EU COST Action 16110 on HUPLANTControl

Chemical pesticides are increasingly confronted with controversy because of concerns related to environmental impact and human health risks associated with residual pesticide levels risk on edible plant-based foods. One of the alternatives is plant protection based on biological control which might include living organisms such as the well-known Bacillus thuringiensis (Bt), a naturally occurring, soil-dwelling bacterium, but taxonomically closely related to human pathogenic Bacillus cereus. Lately, the use of microbial control agents (MCA) – and in particular the use of Bt - as plant protection product has been debated, because these bacterial species used as microbial agents have often also been described as human pathogens. MCAs are often at species level characterized as a microbial hazard with defined pathogenicity whereas human (foodborne) disease is caused by particular strains of these bacterial species or they are defined as opportunistic pathogens and mainly of importance for susceptible consumer groups. Therefore, risk management is not solely based upon ‘hazard identification’ but rather upon ‘risk assessment’. It is common for the usual (primary) foodborne pathogens to define control measures taking into account the base-line situation on microbial contamination, the effect of processing & storage on growth and survival of the microbial agent of concern, the intended use of the food, the category of consumers at risk, the epidemiological evidence of human (foodborne) disease and the overall cost-benefit of the control measure. If no quantitative risk assessment is feasible due to lack of data, decision making will be based on a risk profile and the pre-cautionary principle might apply. However, the precautionary principle in ensuring food safety might overlook the complexity of the agro-food chain and thus benefit from a multi-factor decision-making approach. As such a multi-disciplinary collaboration and common understanding and communication between those involved in pre-harvest (in agriculture dealing with ‘plant production /crop protection’) and those involved post-harvest (in the food supply chain dealing with ‘food quality/food safety’) should be promoted.

The aim of the lunch session is to exchange information and approaches in identifying MCAs as human pathogens or food borne pathogens, and compare approaches in assessing risks or decision-making whether dealing with authorizing plant protection agents or when setting food safety criteria. The session would like to overarch classical disciplines in food and plant microbiology/ecology and welcome researchers to discuss the cost and benefits of ‘plant protection’ and ‘food protection’. The objective of the session is to come up with a common understanding of the terminology and methodology used to facilitate communication between ‘plant/crop’ and ‘food’ scientists on this topic of MCAs and identify needs of further research in evidence-based decision making at the interface when ‘plant becomes food’.

The session is also to be situated within the overall goals of the EU COST Action 16110 ‘Control of Human Pathogenic Micro-organisms in Plant Production Systems (HUPLANTControl ; https://huplantcontrol.igzev.de).