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Use of siderophores to type pseudomonads: the three Pseudomonas aeruginosa pyoverdine systems
Jean-Marie Meyer1, Alain Stintzi1, Daniel De Vos2
1Laboratoire de Microbiologie et de Génétique, Université Louis-Pasteur, Unité de Recherche Associée au Centre National de la Recherche Scientifique No. 1481, 28 rue Goethe, F-67000 Strasbourg, France.
Abstract:
Eighty-eight Pseudomonas aeruginosa isolates, most of them from the Collection of Bacterial Strains of the Institut Pasteur, Paris, were analysed for their pyoverdine-mediated iron incorporation system by different methods, including pyoverdine isoelectrofocusing analysis, pyoverdine-mediated growth stimulation, immunoblot detection of (ferri)pyoverdine outer-membrane receptor and pyoverdine-facilitated iron uptake. The same grouping of the strains was reached by each of these methods, resulting in the classification of the P. aeruginosa isolates, even those which were devoid of pyoverdine production, into three different siderophore types. Forty-two percent of the strains were identified with the type-strain P. aeruginosa ATCC 15,692 (group I), 42% were identical with the second type-strain P. aeruginosa ATCC 27,853 (group II) and 16% reacted identically with the clinical isolate P. aeruginosa Pa6, whose pyoverdine was recognized in this study to be identical in structure to the pyoverdine produced by a natural isolate, P. aeruginosa strain R. No new pyoverdine species was detected among these strains.
Insights
This study classified 88 Pseudomonas aeruginosa strains into three siderophore types based on their pyoverdine-mediated iron uptake systems. Most strains matched known types, with no new pyoverdine species identified.
Area of Science:
- Microbiology
- Bacterial Physiology
- Iron Metabolism
Background:
- Pseudomonas aeruginosa utilizes pyoverdine for iron acquisition, a crucial process for bacterial survival and virulence.
- Variations in pyoverdine structure and function can influence P. aeruginosa's ecological niche and pathogenicity.
- Understanding these variations is key to characterizing P. aeruginosa populations.
Purpose of the Study:
- To classify Pseudomonas aeruginosa isolates based on their pyoverdine-mediated iron incorporation systems.
- To determine the diversity of pyoverdine types within a collection of P. aeruginosa strains.
- To identify if novel pyoverdine species exist in these isolates.
Main Methods:
- Analysis of 88 P. aeruginosa isolates using pyoverdine isoelectrofocusing.
- Assessment of pyoverdine-mediated growth stimulation assays.
- Immunoblot detection of the (ferri)pyoverdine outer-membrane receptor.
- Measurement of pyoverdine-facilitated iron uptake.
Main Results:
- Consistent classification of strains into three distinct siderophore types across all applied methods.
- 42% of isolates belonged to group I (similar to P. aeruginosa ATCC 15,692), 42% to group II (similar to P. aeruginosa ATCC 27,853).
- 16% of isolates matched the pyoverdine type of clinical isolate P. aeruginosa Pa6 and natural isolate P. aeruginosa strain R; no new pyoverdine species were detected.
Conclusions:
- The study successfully categorized P. aeruginosa isolates into three established pyoverdine types, including those lacking pyoverdine production.
- The findings confirm the presence of known pyoverdine types within the analyzed P. aeruginosa collection.
- This classification provides a framework for understanding iron acquisition mechanisms in P. aeruginosa.