title: Identification and role in virulence of putative iron acquisition genes from Corynebacterium pseudotuberculosis.
abstract: Four genes, fagA, B, C and D, encoding products with 32-47% identity to proteins involved in bacterial iron uptake systems, were identified immediately downstream of the Corynebacterium pseudotuberculosis phospholipase D gene. beta-Galactosidase assays on a C. pseudotuberculosis strain carrying a fagA-lacZ fusion indicated that the putative fagABC operon was poorly expressed in iron-rich media. However, similar experiments in iron-limited media resulted in an approximately three-fold increase in beta-galactosidase activity, suggesting that this operon is regulated by iron in vitro. Although no defect in iron utilization could be determined for a C. pseudotuberculosis fagB(C) mutant in vitro, this mutant showed reduced virulence compared to wild-type in a goat model of caseous lymphadenitis. Thus, expression of the fag genes in the host appears to contribute to virulence.
authors.affiliation: Department of Veterinary Science and Microbiology, University of Arizona, 1117 E. Lowell Street, Tucson, AZ 85721, USA. sbilling@u.arizona.edu
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Billington
authors.forename: Paula A
authors.initials: PA
authors.lastname: Esmay
authors.forename: J Glenn
authors.initials: JG
authors.lastname: Songer
authors.forename: B Helen
authors.initials: BH
authors.lastname: Jost
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003354:Corynebacterium Infections / Q000382:microbiology / Q000662:veterinary*; D016925:Corynebacterium pseudotuberculosis / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D015511:Goat Diseases / Q000382:microbiology*; D006041:Goats; D007501:Iron / Q000378:metabolism*; D008199:Lymphadenitis / Q000382:microbiology / Q000662:veterinary*; D008969:Molecular Sequence Data; D009154:Mutation; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D007501:Iron