Understanding the role of lactose, glucose, and galactose on the composition of E. coli extracellular polymeric substances and antibiotic sensitivity
Location
CELA & Mary Church Terrell Library, First Floor
Document Type
Poster - Open Access
Start Date
4-25-2025 12:00 PM
End Date
4-25-2025 2:00 PM
Research Program
NSF (MCB 2226953)
Abstract
Biofilm is a complex matrix of bacterial cells and extracellular polymeric substances adopted by bacteria most commonly during periods of environmental stress. In this state, bacteria exhibit increased resistance to antibiotics. Documenting the influence of sugar metabolism on biofilm growth, composition, and antibiotic sensitivity provides useful insight into environmental conditions that exacerbate or prevent biofilm growth. Specifically, we focused on the impact of lactose, a non-phosphotransferase disaccharide which has a separate, controlled pathway for uptake into the bacterial cell, and its impacts on biofilm growth, composition, and antibiotic sensitivity in Escherichia coli (E. coli). Additionally, we investigated whether the two monosaccharide components of lactose, glucose and galactose, have similar impacts as lactose either collectively or independently. Crystal violet assays, staining of biofilm followed by confocal imaging, and growth of E. coli on agar plates followed by protein and carbohydrate assays allowed for biofilm growth and composition quantification. Additionally, disk diffusion and microbroth dilutions were carried out to determine the susceptibility of E. coli under differing growth conditions to several antibiotics. In the presence of lactose, and glucose and galactose, administered simultaneously and separately, E. coli susceptibility to multiple fluoroquinolones and macrolides decreased while susceptibility increased for an antimycobacterial agent. Ultimately, knowledge about the intersection and influence of sugar metabolism, biofilm formation and composition, and antibiotic susceptibility will lead to developments that disrupt biofilm formation or allow better control of biofilm-associated infections.
Keywords:
E. coli, Biofilm, Antibiotic sensitivity, Sugar
Recommended Citation
Foley, Molly; Garcia, Guadalupe Marino; and Ryno, Lisa, "Understanding the role of lactose, glucose, and galactose on the composition of E. coli extracellular polymeric substances and antibiotic sensitivity" (2025). Research Symposium. 9.
https://digitalcommons.oberlin.edu/researchsymp/2025/posters/9
Major
Biochemistry
Horn Performance
Project Mentor(s)
Lisa Ryno, Chemistry and Biochemistry
2025
Understanding the role of lactose, glucose, and galactose on the composition of E. coli extracellular polymeric substances and antibiotic sensitivity
CELA & Mary Church Terrell Library, First Floor
Biofilm is a complex matrix of bacterial cells and extracellular polymeric substances adopted by bacteria most commonly during periods of environmental stress. In this state, bacteria exhibit increased resistance to antibiotics. Documenting the influence of sugar metabolism on biofilm growth, composition, and antibiotic sensitivity provides useful insight into environmental conditions that exacerbate or prevent biofilm growth. Specifically, we focused on the impact of lactose, a non-phosphotransferase disaccharide which has a separate, controlled pathway for uptake into the bacterial cell, and its impacts on biofilm growth, composition, and antibiotic sensitivity in Escherichia coli (E. coli). Additionally, we investigated whether the two monosaccharide components of lactose, glucose and galactose, have similar impacts as lactose either collectively or independently. Crystal violet assays, staining of biofilm followed by confocal imaging, and growth of E. coli on agar plates followed by protein and carbohydrate assays allowed for biofilm growth and composition quantification. Additionally, disk diffusion and microbroth dilutions were carried out to determine the susceptibility of E. coli under differing growth conditions to several antibiotics. In the presence of lactose, and glucose and galactose, administered simultaneously and separately, E. coli susceptibility to multiple fluoroquinolones and macrolides decreased while susceptibility increased for an antimycobacterial agent. Ultimately, knowledge about the intersection and influence of sugar metabolism, biofilm formation and composition, and antibiotic susceptibility will lead to developments that disrupt biofilm formation or allow better control of biofilm-associated infections.
Notes
Presenter: Molly Foley