Prevalence, behavior and risk assessment of Salmonella spp. and Shiga toxin-producing Escherichia coli on basil leaves and strawberries

Abstract

Consumption of fresh fruits and vegetables (F&V) is important for a healthy and balanced diet due to the presence of vitamins, minerals, fibres and other dietary components. However, F&V, in particular leafy green vegetables, that are consumed raw, have been associated with some notable outbreaks of microbial foodborne disease. Within this context and due the lack of data relating to the prevalence and behaviour of pathogens on F&V, the EU FP7 Veg-i-Trade project was developed. This PhD research deals with the microbiological analysis and exposure assessment of particular case studies of F&V being Salmonella and STEC in strawberries and basil. The objective of the PhD research was (i) to collect information about the prevalence of Salmonella and STEC on basil and strawberries and to investigate the behaviour of these pathogens during the storage of these commodities at different reasonably foreseen temperatures and (ii) subsequently use the obtained data as input in the comparative exposure assessment model for a quantitative risk ranking. To do so, first detection methods (i.e. the GeneDisc multiplex real-time PCR kit and culture methods for detection of Salmonella and STEC) needed some evaluation for their appropriateness in use for these specific food products (iii). In addition, exposure to pathogens due to consumption of basil and strawberries were compared to exposure to already prior well studied lettuce as a leafy green