Isolation and characterization of Bordetella bronchiseptica mutants deficient in siderophore activity.

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Sandra K. Armstrong (Creator)

Mark O. Clements (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

Abstract: Iron acquisition by the gram-negative pathogens Bordetella bronchiseptica and Bordetella pertussis is thought to occur by hydroxamate siderophore-mediated transport as well as an apparently siderophore-independent process by which host transferrins bind to bacterial surface receptors. We constructed B. bronchiseptica mutants deficient in siderophore activity by insertional mutagenesis with miniTn5/LacZl. The mutants could be placed into four distinct complementation groups as determined from cross-feeding assays which demonstrated restored siderophore synthesis. Mutants deficient in siderophore activity were BRM1 BRM6 and BRM9 exhibiting approximately 36 to 41% of wild-type siderophore levels and BRM3 and BRM8 which appeared to produce very little or no detectable siderophore. Mutant BRM4 was found to be a leucine auxotroph while mutants BRM2 and BRM7 could synthesize siderophore only in low-iron medium which was supplemented with various amino acids. Evaluation of all transcriptional fusions revealed an apparent lack of iron-regulated lacZ expression. Genomic regions flanking the transposable element in the siderophore mutants were homologous with B. pertussis chromosomal DNA while bioassays suggested siderophore cross-feeding between B. pertussis and B. bronchiseptica. These results indicate probable similarity between the siderophore biosynthetic and transport systems of the two species. Originally published Journal of Bacteriology Vol. 175 No. 4 Feb 1993

Additional Information

Publication

Other

Journal of Bacteriology. 175:4(February 1993) p. 1144-1152.

Language: English

Date: 2011

Keywords

Bordetella bronchiseptica, siderophore activity, iron acquisition

Email this document to