Risk assessment of Escherichia coli O157:h7, Listeria monocytogenes, Salmonella enterica subsp. Enterica serovar typhimurium and Staphylococcus aureus within a stone fruit production environment

Abstract

In recent years there has been a global increase in fresh produce associated foodborne disease outbreaks caused by Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium and Staphylococcus aureus. Fruit and vegetables can become contaminated at various points along the supply chain. Therefore there is a great need for food safety assurance of fresh fruit and vegetables produced on farm. South Africa is a large exporter of peaches and plums and a lack of an effective food safety assurance system could hamper market access and eventually result in a barrier to trade. The aim of this study was to determine the level of risk associated with peaches and plums produced in South Africa. In order to address the overall aim of the study an effective foodborne pathogen molecular detection system in a form of a multiplex PCR was developed and used in monitoring water, fruit and environmental samples. This detection system formed part of the developed framework to assess the possible exposure of fresh produce and to identify the presence of hazards on farm. An aspect of the study was to determine effectiveness of on-farm horticultural safety management system (HSMS) and to make recommendations to primary producers that would allow them to increase food safety assurance. Following the semi-quantitative risk assessment conducted the overall findings showed that peaches and plums were considered low risk commodities, due to the low incidence of fruit contamination in the sample size, as well as the pathogens inability to grow and survive on fruit through a simulated export chain to titres that would exceed the infectious dose of the organism. In conclusion, peaches and plums in this study that were bound for export were found to be safe for consumption, with the risk to the international consumer being low.