title: Identification of Staphylococcus aureus genes expressed during growth in milk: a useful model for selection of genes important in bovine mastitis?
abstract: Staphylococcus aureus is a major cause of bovine mastitis. Since gene expression of many bacteria is known to be regulated by the environment, milk may play an important role in the regulation of the early steps in the pathogenesis of bovine mastitis by S. aureus. To get insight into the response of S. aureus to the milk environment, a Tn917-lacZ mutant library was generated and screened for genes specifically expressed during growth in milk. Twenty-eight mutants were identified and analysed. Four groups of genes were found, involved in cell-wall synthesis, nucleotide synthesis, transcriptional regulation and carbohydrate metabolism. A fifth group contained genes with hypothetical or unknown functions. Many of the genes identified belonged to biosynthetic pathways of S. aureus and other bacterial species which have also been shown to play a role in vivo as determined in murine infection models. Therefore, growth on milk may be an attractive model for the identification of genes preferentially expressed during bovine mastitis.
authors.affiliation: Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1.
authors.forename: Aart
authors.initials: A
authors.lastname: Lammers
authors.affiliation: Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1.
authors.forename: Ellard
authors.initials: E
authors.lastname: Kruijt
authors.affiliation: Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1.
authors.forename: Corine
authors.initials: C
authors.lastname: van de Kuijt
authors.affiliation: Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1.
authors.forename: Piet J M
authors.initials: PJM
authors.lastname: Nuijten
authors.affiliation: Department of Bacteriology, Institute for Animal Science and Health, PO Box 65, 8200 AB Lelystad, The Netherlands1.
authors.forename: Hilde E
authors.initials: HE
authors.lastname: Smith
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008414:Mastitis, Bovine / Q000382:microbiology; D008892:Milk / Q000382:microbiology; D008969:Molecular Sequence Data; D013211:Staphylococcus aureus / Q000235:genetics* / Q000254:growth & development