Salmonella Biomapping of a Commercial Broiler Hatchery

Authors: Rothrock, Michael; AL HAKEEM, WALID - Department Of Energy; Oladeinde, Adelumola - Ade; Looft, Torey; Li, Xiang; GUARD, JEAN - Former ARS Employee

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2024
Publication Date: 8/14/2024
Citation: Rothrock Jr, M.J., Al Hakeem, W., Oladeinde, A.A., Looft, T.P., Li, X., Guard, J. 2024. Salmonella Biomapping of a Commercial Broiler Hatchery. Journal of Food Protection. //doi.org/10.1016/j.jfp.2024.100347.
DOI: https://doi.org/10.1016/j.jfp.2024.100347

Interpretive Summary: Poultry-associated salmonellosis results in significant costs to poultry producers and consumers. Given the vertically integrated nature of the United States poultry industry, a better understanding of Salmonella ecology throughout all levels of poultry production is essential. One nexus point is the hatchery, where eggs from multiple broiler breeder farms are incubated and hatched, with the chicks being sent to numerous farms; therefore, the hatchery represents an ideal area to understand pre-harvest Salmonella ecology and flow. To achieve this, a commercial broiler hatchery was biomapped, focusing on Salmonella prevalence and serotype diversity among four major sample type categories (Air, Egg, Water, Facility) across five different places in the pre-hatch, hatch, and post-hatch areas. Following two sets of eggs from broiler breeder farms over two production days, Salmonella prevalence was 26% (48/184), with prevalence highest in swabs of floor drains in the facility and transport truck (56%) and in the hatch and post-hatch hatchery areas (50%). Kentucky (n=17), Gaminara (n=12), and Alachua (n=11) were the dominant Salmonella serotypes, with serotypes of greatest outbreak concern from chickens (Enteritidis) representing only 6.25% (3/48) of all recovered Salmonella isolates. The post-hatch transport area, including the underfloor reservoirs of the transport trucks, not only harbored Enteritidis, but the enrichment broths from these Salmonella positive samples also possessed sequences matching the commercial live-attenuated vaccine Typhimurium strain according to CRISPR SeroSeq analyses. These findings highlight the complex diversity of commercial hatchery Salmonella populations, including identifying facility floor drains and transport trucks as potentially important critical control points for hatchery managers to focus their Salmonella mitigation efforts to reduce loads and serotypes entering live production farms.

Technical Abstract: Poultry-associated salmonellosis results in significant costs to poultry producers and consumers. Given the vertically integrated nature of the United States poultry industry, a better understanding of Salmonella ecology throughout all levels of poultry production is essential. One nexus point is the hatchery, where eggs from multiple broiler breeder farms are incubated and hatched, with the chicks being sent to numerous farms; therefore, the hatchery represents an ideal area to understand pre-harvest Salmonella ecology and flow. To achieve this, a commercial broiler hatchery was biomapped, focusing on Salmonella prevalence and serotype diversity among four major sample type categories (Air, Egg, Water, Facility) across five different places in the pre-hatch, hatch, and post-hatch areas. Following two sets of eggs from broiler breeder farms over two production days, Salmonella prevalence was 26% (48/184), with prevalence highest in swabs of floor drains in the facility and transport truck (56%) and in the hatch and post-hatch hatchery areas (50%). Kentucky (n=17), Gaminara (n=12), and Alachua (n=11) were the dominant Salmonella serotypes, with serotypes of greatest outbreak concern from chickens (Enteritidis) representing only 6.25% (3/48) of all recovered Salmonella isolates. The post-hatch transport area, including the underfloor reservoirs of the transport trucks, not only harbored Enteritidis, but the enrichment broths from these Salmonella positive samples also possessed sequences matching the commercial live-attenuated vaccine Typhimurium strain according to CRISPR SeroSeq analyses. These findings highlight the complex diversity of commercial hatchery Salmonella populations, including identifying facility floor drains and transport trucks as potentially important critical control points for hatchery managers to focus their Salmonella mitigation efforts to reduce loads and serotypes entering live production farms.