Foodborne Pathogen Ecology Throughout the Pastured Poultry Farm-to-Fork Continuum

Authors: Rothrock, Michael

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/28/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: There has been an increased demand for non-conventional raised poultry in the US, with these types of “alternative” poultry products accounting for upwards a 20% of all poultry products sold in the US. While this consumer-driven shift has resulted in this increase of alternative production, there is limited scientific data regarding any potential food safety-related issues within these systems. Therefore, the goal of this study was to look at major foodborne bacterial pathogens (Salmonella, Campylobacter, Listeria) and an indicator (E. coli) throughout the farm-to-fork continuum to see how different management or environmental/physiochemical variables effect the ecology of these bacteria. To achieve this, live production (feces, pasture soil), processing (ceca, whole carcass rinses) and final product (whole carcass rinses) samples were collected from 42 flocks from 11 pastured poultry farms from 2014 – 2017. The four foodborne pathogens were either quantified and recovered (Campylobacter, E. coli) and enriched for (Salmonella, Listeria) using traditionally used culture techniques, and select isolates were further characterized via speciation, subtyping, antimicrobial sensitivity testing (using the CDC NARMS panels). In general, Campylobacter and E. coli numbers were highest during live production, and greatly decreased during processing through to the final product. In terms of Salmonella and Listeria, the recovered isolated came from all sample types, but a majority of both were not characterized as posing significant threats to human health (predominantly serotype Kentucky for Salmonella, and L. innocua or L. welshimeri). In terms of antibiotic resistance of the bacteria from these antibiotic-free management systems, the four bacteria demonstrated different levels of resistance, with some of these differences being based on farm of origin. The results from this large study highlight to importance of continued food safety work to understand the ecological dynamics of these pathogens within this growing poultry management system.

Technical Abstract: There has been an increased demand for non-conventional raised poultry in the US, with these types of “alternative” poultry products accounting for upwards a 20% of all poultry products sold in the US. While this consumer-driven shift has resulted in this increase of alternative production, there is limited scientific data regarding any potential food safety-related issues within these systems. Therefore, the goal of this study was to look at major foodborne bacterial pathogens (Salmonella, Campylobacter, Listeria) and an indicator (E. coli) throughout the farm-to-fork continuum to see how different management or environmental/physiochemical variables effect the ecology of these bacteria. To achieve this, live production (feces, pasture soil), processing (ceca, whole carcass rinses) and final product (whole carcass rinses) samples were collected from 42 flocks from 11 pastured poultry farms from 2014 – 2017. The four foodborne pathogens were either quantified and recovered (Campylobacter, E. coli) and enriched for (Salmonella, Listeria) using traditionally used culture techniques, and select isolates were further characterized via speciation, subtyping, antimicrobial sensitivity testing (using the CDC NARMS panels). In general, Campylobacter and E. coli numbers were highest during live production, and greatly decreased during processing through to the final product. In terms of Salmonella and Listeria, the recovered isolated came from all sample types, but a majority of both were not characterized as posing significant threats to human health (predominantly serotype Kentucky for Salmonella, and L. innocua or L. welshimeri). In terms of antibiotic resistance of the bacteria from these antibiotic-free management systems, the four bacteria demonstrated different levels of resistance, with some of these differences being based on farm of origin. The results from this large study highlight to importance of continued food safety work to understand the ecological dynamics of these pathogens within this growing poultry management system.