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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Poultry Microbiological Safety and Processing Research Unit » Research » Publications at this Location » Publication #421793
Research Project: Intervention Strategies to Control Salmonella and Campylobacter During Poultry Processing

Location: Poultry Microbiological Safety and Processing Research Unit

Title: Ferric Uptake Regulator (Fur) plays a significant role in the survival of Salmonella Typhimurium on meat

Author
item BHARATHAN, GREESHMA - Auburn University
item CHINCHILLA, KAROLL - Zamorano, Panamerican School Of Agriculture
item SHEFFIELD, HUNTER - Auburn University
item HAYDEN, MICHELLE - Auburn University
item MADI, AISHA - Auburn University
item Buhr, Richard
item SRIKUMAR, SHABARINATH - Auburn University

Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: 11/25/2024
Publication Date: 1/27/2025
Citation: Bharathan, G., Chinchilla, K.E., Sheffield, H., Hayden, M., Madi, A., Buhr, R.J., Srikumar, S. 2025. Ferric Uptake Regulator (Fur) plays a significant role in the survival of Salmonella Typhimurium on meat. International Poultry Scientific Forum. 104(E.Suppl.1): 33.

Interpretive Summary:

Technical Abstract: Food is an important source of Salmonella infections, and poultry products are one of the leading causes of disease outbreaks. The success of Salmonella Typhimurium as a pathogen lies in its ability to adapt to the changing environment quickly. This adaptability of the bacterium is strictly regulated by numerous DNA-binding transcriptional regulatory factors that respond to signals from the external environment. To identify the factors that are critical for the survival of Salmonella on meat, different deletion mutants of transcriptional regulatory factors of Salmonella Typhimurium ST 4/74 were grown on chicken meat pieces (breast fillets-1 gram piece each), incubated at 37C and aliquots were plated onto XLD agar plates. The bacterial counts in CFU/mL were plotted against time to plot the growth curves. Of the 9 deletion mutants, ST4/74'fur (Ferric Uptake Regulator) was highly inhibited compared to the wild type. Fur protein, during iron-replete conditions, represses the siderophore production gene. On exhaustion of free iron in the environment, Fur protein is released, thereby activating the different siderophore genes, which allows the bacterium to chelate the iron (Fe3+) bound to various proteins from the environment. Taking clues from the previous study in milk, inhibition of fur deletion mutant could be due to an intracytoplasmic iron accumulation, which could be toxic to the bacterium. To have a better understanding of iron regulation, we deleted the gene for enterochelin production, a major siderophore in Salmonella (entC). ST4/74'entC grew similar to the wild type, relaxing the inhibition from fur deletion. This led to the hypothesis that the deletion of the entC siderophore gene blocked the uptake of iron by the bacteria, thereby reducing the iron toxicity in the cytoplasm, which aided in a revival of the growth of the bacterium on the meat surface. Furthermore, the double mutant ST4/74'fur'entC also did not show a significant reduction in growth when compared to the wild type. Our data gives preliminary insights into how iron uptake by Salmonella Typhimurium in iron-rich meat is strictly regulated by fur and aids in the colonization of the food matrix.