[Effect of iron on Pasteurella multocida]

Area of Science:

• Microbiology
• Bacterial Pathogenesis
• Iron Metabolism

Background:

• Iron is crucial for the growth, virulence, and immunogenicity of Pasteurella multocida.
• Previous studies in vitro and in vivo (mice, piglets, calves) have highlighted iron's importance.
• The specific iron uptake mechanisms of P. multocida remain largely uncharacterized.

Purpose of the Study:

• To investigate the iron transport system of Pasteurella multocida.
• To determine which iron sources are available for P. multocida growth and iron assimilation.
• To assess the impact of various iron chelating agents on P. multocida.

Main Methods:

• In vitro experiments using bacterial cultures.
• Radioactive iron (Fe-59) tracer studies to monitor iron uptake.
• Testing the effects of diverse iron substrates and chelating agents on bacterial growth and iron incorporation.

Main Results:

• P. multocida can acquire iron from physiological sources like heme, ferritin, transferrin, and lactoferrin.
• Iron from iron dextran and low molecular weight iron compounds is available to P. multocida.
• Certain iron chelators (e.g., alpha,alpha'-dipyridyl, phenanthroline, deferrioxamine B, enterobactin) inhibit P. multocida growth and iron uptake, while others have minimal effect.

Conclusions:

• P. multocida possesses a versatile iron transport system capable of utilizing various iron sources.
• Enterobactin and deferrioxamine B, common siderophores, do not appear to be involved in P. multocida iron transport.
• Understanding P. multocida's iron acquisition is key to developing strategies against infections caused by this pathogen.