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Miller, K. (2021). Effect of Organic Iron on Growth, Motility, and Virulence of Salmonella Typhimurium. Retrieved from https://purl.lib.fsu.edu/diginole/2021_Summer_Miller_fsu_0071N_16742
Background: Iron-containing micronutrient powders may increase the risk and severity of enteric infections. Unabsorbed iron in the lower intestine may increase severity of infection by promoting the growth of gram-negative enteric pathogens. These findings indicate a need for alternative iron sources to correct or prevent iron deficiency without increasing the risk or severity of infection. Aspergillus oryzae (Ao) is a filamentous fungus that has the ability to accumulate large amounts of iron and store it in vacuoles. Thus, iron-enriched Ao may not be available to enteric pathogens. Objective: The objective of this study was to determine the effect of concentration and source of iron (FeSO₄ and FeSO₄-enriched Ao) on the growth and virulence of the gram-negative enteric pathogen, Salmonella enterica subspecies enterica serovar Typhimurium. Method: Salmonella was grown in media containing varying concentrations of iron as FeSO₄ (iron) or FeSO₄-enriched Ao (Ao iron) or media without iron (n=5/treatment). Growth curves were generated by measuring OD₆₀₀ every 15 minutes for 12 hours. Slides were prepared at 6.5 hr into incubation and videos were taken of sections of each slide (n=7 slides/treatment x 5 videos/slide). Bacterial tracking and analyses were performed using NIS-Element Analysis AR software. Slides were prepared using RYU Flagella Stain. Random sections of each slide (n=5/treatment) were photographed and analyzed using Fiji ImageJ software to measure flagella present. Data are presented as means ±SD. Results: Greater Salmonella growth was observed in bacteria grown in media containing iron compared to both no iron (P<0.0001) and Ao iron (P<0.0001). Area under the curve analysis demonstrated 44% and 37% greater growth in Salmonella grown in iron compared to no iron(P<0.0001) and Ao iron (P<0.0001) respectively. Salmonella grown in Ao iron showed 5% greater growth than Salmonella grown in no iron (P<0.0001). Salmonella grown in iron were 98% faster than those grown in no iron (P<0.0001) and 65% faster than those grown in Ao iron (P<0.0001). The velocity of Salmonella grown in Ao did not differ from those grown in no iron (P=0.08). Salmonella grown with iron showed 84% and 46% greater acceleration than those grown in no iron or Ao iron respectively. Salmonella traveled 65% further when grown in iron compared to no iron (P=0.03) and Ao iron (P<0.04). Flagella length did not differ between groups. Conclusions: Iron-enriched Ao attenuated the growth and motility of Salmonella compared to iron alone. These findings provide evidence that iron-enriched Ao may be a suitable alternative to correct iron deficiency or iron deficiency anemia without increase in risk of severity of infection.
A Thesis submitted to the Department of Nutrition and Integrative Physiology in partial fulfillment of the requirements for the degree of Master of Science.
Bibliography Note
Includes bibliographical references.
Advisory Committee
Stephen Hennigar, Professor Directing Thesis; Prashant Singh, Committee Member; Jamel Ali, Committee Member.
Publisher
Florida State University
Identifier
2021_Summer_Miller_fsu_0071N_16742
Miller, K. (2021). Effect of Organic Iron on Growth, Motility, and Virulence of Salmonella Typhimurium. Retrieved from https://purl.lib.fsu.edu/diginole/2021_Summer_Miller_fsu_0071N_16742