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Siderophore production by Pseudomonas pseudomallei
H M Yang1, W Chaowagul, P A Sokol
1Department of Microbiology and Infectious Diseases, University of Calgary Health Science Centre, Alberta, Canada.
Abstract:
Eighty-four strains of Pseudomonas pseudomallei isolated from patients with melioidosis were examined for siderophore production. All the strains were shown to produce siderophore both on chrome azurol S agar plates and in liquid medium under iron-deficient conditions. Chemical assays indicated that the siderophore belongs to the hydroxamate class. Addition of iron to the culture medium resulted in increased culture growth with markedly decreased yield of siderophore. Siderophore produced by strain U7 was purified by gel filtration chromatography, and the molecular weight was estimated to be 1,000. When this partially purified siderophore was added to culture medium, it promoted iron uptake by P. pseudomallei in the presence of EDTA and enhanced growth of the organism in the presence of transferrin. We have given this siderophore the trivial name malleobactin.
Insights
All tested Pseudomonas pseudomallei strains produce siderophores, a hydroxamate-class compound named malleobactin. This siderophore enhances iron uptake and growth in iron-limited conditions, crucial for understanding melioidosis pathogenesis.
Area of Science:
- Microbiology
- Biochemistry
Background:
- Melioidosis is caused by Pseudomonas pseudomallei.
- Iron acquisition is vital for bacterial pathogens.
Purpose of the Study:
- To investigate siderophore production in Pseudomonas pseudomallei.
- To characterize the siderophore and its role in iron metabolism.
Main Methods:
- Siderophore production assessed on chrome azurol S agar and liquid media.
- Chemical assays identified siderophore class.
- Gel filtration chromatography used for purification.
- Iron uptake and growth promotion assays performed.
Main Results:
- All 84 Pseudomonas pseudomallei strains produced siderophores.
- The siderophore is of the hydroxamate class.
- Purified siderophore (malleobactin) enhanced iron uptake and growth in iron-limited conditions.
- Iron addition decreased siderophore yield and increased growth.
Conclusions:
- Pseudomonas pseudomallei produces a hydroxamate siderophore, malleobactin.
- Malleobactin plays a significant role in iron acquisition for Pseudomonas pseudomallei.
- Understanding malleobactin is important for melioidosis treatment strategies.