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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Egg and Poultry Production Safety Research Unit » Research » Publications at this Location » Publication #420172
Research Project: Reduction of Foodborne Pathogens and Antimicrobial Resistance in Poultry Production Environments

Location: Egg and Poultry Production Safety Research Unit

Title: Fitness factors and siderophores influence the survival of E. coli in reused broiler litter

Author
item Oladeinde, Adelumola
item CHUNG, TAEJUNG - Department Of Energy
item WOYDA, REED - Colorado State University
item Wickramasuriya, Samiru
item Lyte, Joshua
item LIYANAGE, ROHANA - University Of Arkansas
item Rothrock Jr, Michael
item Li, Xiang
item Cho, Sohyun
item Plumblee Lawrence, Jodie
item Endale, Dinku
item Strickland, Timothy
item ABDO, ZAID - Colorado State University

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2025
Publication Date: 11/19/2025
Citation: Oladeinde, A.A., Chung, T., Woyda, R., Wickramasuriya, S.S., Lyte, J.M., Liyanage, R., Rothrock Jr, M.J., Li, X., Cho, S., Plumblee Lawrence, J.R., Endale, D.M., Strickland, T.C., Abdo, Z. 2025. Fitness factors and siderophores influence the survival of E. coli in reused broiler litter. Journal of Food Protection. doi.org/10.1016/j.jfp.2025.100671
DOI: https://doi.org/10.1016/j.jfp.2025.100671

Interpretive Summary: In the United States and Brazil, broiler litter is reused across multiple flocks to save money and to provide a competitive and complex environment that can limit pathogen invasion. Nonetheless, litter reuse can serve as a major route for bacterial transmission to new flocks. While E. coli is typically a harmless gut bacterium, certain strains can cause serious health issues in humans and poultry. Furthermore, E. coli can act as a reservoir for antimicrobial resistance (AMR) and virulence factor (VF) genes, which may be transferred to other pathogens. This research utilizes whole genome sequencing of 217 E. coli isolates from successive flocks and broiler houses to explore how environmental and management factors influence the fitness factors genes. The findings could inform strategies to mitigate the spread of fitness factors, enhancing food safety and public health.

Technical Abstract: Escherichia coli is a common bacterium in poultry that can be considered as commensal bacterium. However, E. coli can not only show virulence toward human and poultry but also harbor antimicrobial resistance (AMR) and virulence factor (VF) genes. This study investigated the genomic characteristics of 217 E. coli isolates recovered from three successive reused broiler litter from four broiler houses to identify associations between fitness factors (AMR and VF genes) and management (flock cohort, house, section, area, and grow-out period) or environmental (broiler house temperature, litter pH, and moisture content) factors. Results showed diverse E. coli strains across flocks, with phylogroups A and B1 being most prevalent. A few sequence types such as ST10, ST212, and ST117 were frequently observed across all flocks. Isolates from the first flock harbored more diverse fitness factors, including metal resistance genes and siderophore biosynthesis operons and exhibited greater antimicrobial resistance, suggesting more fitness factors are required to adapt to a new environment and to compete with other bacteria. No significant correlations were found between fitness factors and spatial management factors such as broiler house, sampling section and area, or environmental factors. This study provides insights into the E. coli genomic content in reused broiler litter, highlighting the importance of management practices in controlling potential pathogens and antimicrobial resistance gene reservoir in poultry production environments. Further research is needed to elucidate the long-term effects of litter reuse on E. coli populations and their associated fitness factors.