Related Experiment Videos
Effect of iron limitation on protein composition and ultrastructure of Haemophilus ducreyi
D Abeck1, A P Johnson, H C Korting
1Department of Dermatology, Ludwig-Maximilians-University, Munich, F.R.G.
Abstract:
Protein profiles of whole cells of Haemophilus ducreyi grown in the presence or absence of the iron chelator desferal, were compared by polyacrylamide gel electrophoresis. Each of four strains produced novel proteins in the range 43-160 kDa when cultured under conditions of reduced iron availability. At some sub-inhibitory concentrations, desferal produced enhanced growth, possibly due to it functioning as an exogenous siderophore. Organisms grown under conditions of reduced iron availability ultrastructurally showed also large periplasmic spaces between cytoplasm and outer membrane.
Insights
Haemophilus ducreyi produces new proteins when iron is scarce. Reduced iron availability also causes structural changes in the bacteria, potentially due to desferal acting as a siderophore.
Area of Science:
- Microbiology
- Bacterial Physiology
- Protein Expression
Background:
- Haemophilus ducreyi is a Gram-negative bacterium causing chancroid.
- Iron is an essential nutrient for bacterial growth and virulence.
- Iron availability significantly impacts bacterial gene expression and protein profiles.
Purpose of the Study:
- To investigate the changes in protein profiles of Haemophilus ducreyi under iron-limited conditions.
- To determine the effect of the iron chelator desferal on bacterial growth and ultrastructure.
Main Methods:
- Polyacrylamide gel electrophoresis (PAGE) was used to compare protein profiles.
- Haemophilus ducreyi strains were cultured with and without desferal.
- Ultrastructural analysis was performed on bacteria grown under iron limitation.
Main Results:
- Four strains of H. ducreyi produced novel proteins (43-160 kDa) when iron availability was reduced.
- Desferal at sub-inhibitory concentrations enhanced bacterial growth, suggesting it may act as an exogenous siderophore.
- Iron-limited growth resulted in enlarged periplasmic spaces in H. ducreyi.
Conclusions:
- Iron availability significantly influences the proteome of Haemophilus ducreyi.
- Desferal can modulate H. ducreyi growth and may serve as a siderophore.
- Reduced iron leads to observable ultrastructural alterations in H. ducreyi, impacting cell morphology.