title: Potential for transfer of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella Senftenberg from contaminated food waste derived compost and anaerobic digestate liquid to lettuce plants.
abstract: The diversion of food wastes from landfill to sustainable disposal methods, such as composting and anaerobic digestion, has led to an increase in the soil amendment products that are now commercially available and which are derived from both of these processes. The use of such products as soil amendments during the production of ready-to-eat (RTE) crops is increasing worldwide. The aim of this study was to investigate the potential of three well-recognised bacterial pathogens of importance to public health, namely Escherichia coli O157:H7, Salmonella Senftenberg and Listeria monocytogenes, to become internalised in lettuce plants from peat growing media amended with contaminated food waste derived compost and anaerobic digestion liquid. The results demonstrated both S. Senftenberg and E. coli O157:H7 are capable of internalisation at lower inoculation levels, compared to previous studies. The internalisation was visualised through confocal microscopy. Internalisation of L. monocytogenes did not occur, however significant levels of L. monocytogenes contamination occurred on the non-sterilised plant surface. Assessing the internalisation potential for each of these pathogens, through the compost and anaerobic digestate matrices, allows for better risk assessment of the use of these products in a horticultural setting.
authors.affiliation: Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland; UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Suzannah
authors.initials: S
authors.lastname: Murphy
authors.affiliation: Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland; Horticulture Development Department, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Gaffney
authors.affiliation: UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, Belfield, Dublin 4, Ireland; Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, United Kingdom.
authors.forename: Seamus
authors.initials: S
authors.lastname: Fanning
authors.affiliation: Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland. Electronic address: kaye.burgess@teagasc.ie.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Burgess
mesh_terms: D000693:Anaerobiosis; D058491:Bacterial Load; D003470:Culture Media; D019453:Escherichia coli O157 / Q000472:pathogenicity / Q000502:physiology* / Q000648:ultrastructure; D005308:Fertilizers / Q000382:microbiology; D005516:Food Microbiology; D006801:Humans; D018545:Lactuca / Q000254:growth & development / Q000382:microbiology*; D008089:Listeria monocytogenes / Q000472:pathogenicity / Q000502:physiology* / Q000648:ultrastructure; D008372:Manure; D050296:Microbial Viability; D018613:Microscopy, Confocal; D018570:Risk Assessment; D019779:Salmonella enterica / Q000472:pathogenicity / Q000502:physiology* / Q000648:ultrastructure; D012987:Soil; D012988:Soil Microbiology; D014871:Water Microbiology
chemical_list: D003470:Culture Media; D005308:Fertilizers; D008372:Manure; D012987:Soil
keywords: Contaminated fertilisers; Foodborne pathogens; Plant uptake