A novel siderophore‐independent strategy of iron uptake in the genus Burkholderia. Issue 4 (13th January 2014)

• Record Type: Journal Article
• Authors: Mathew, Anugraha; Eberl, Leo; Carlier, Aurelien L.
• Is Part Of: Molecular microbiology. Volume 91:Issue 4(2014)
• Page Start: 805
• Page End: 820
• Publication Date: 2014-01-13
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12499
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Like many other bacteria, <italic>B</italic><italic>urkholderia </italic>sp. take up iron in its ferric form <italic>via</italic> siderophore‐dependent transporters. We observed that mutant strains of <italic>B</italic>. <italic>cenocepacia</italic> H111 unable to synthesize siderophores did not exhibit any growth defect under iron limited conditions. This finding suggested that this opportunistic pathogen can adopt an alternative iron uptake strategy to compensate for the loss of siderophores. We identified a putative iron uptake locus, <italic>ftr<sub>Bcc</sub>ABCD</italic>, in the genome of <italic>B</italic>. <italic>cenocepacia</italic> H111, which is also conserved in other members of the genus <italic>B</italic><italic>urkholderia</italic>. Mutants deficient in both siderophore‐dependent and Ftr<sub>Bcc</sub>ABCD systems failed to grow under iron‐limited conditions and radiolabelled iron transport assays showed that these mutants were impaired in iron uptake. In addition, expression of <italic>ftr<sub>Bcc</sub>ABCD</italic> can restore growth of an <italic>E</italic>. <italic>coli </italic>strain lacking all known high‐affinity iron transport systems under iron‐limited conditions. We show that all four proteins encoded by <italic>ftr<sub>Bcc</sub>ABCD</italic> are essential for iron uptake. Furthermore, our results indicate that the expression of <italic>ftr<sub>Bcc</sub>ABCD</italic> is regulated at the transcriptional level by iron concentration. This study provides evidence of an alternative, siderophore‐independent, iron uptake system in <italic>B</italic><italic>urkholderia</italic> species.</p> </abstract>