title: Production of the Bsa lantibiotic by community-acquired Staphylococcus aureus strains.
abstract: Lantibiotics are antimicrobial peptides that have been the focus of much attention in recent years with a view to clinical, veterinary, and food applications. Although many lantibiotics are produced by food-grade bacteria or bacteria generally regarded as safe, some lantibiotics are produced by pathogens and, rather than contributing to food safety and/or health, add to the virulence potential of the producing strains. Indeed, genome sequencing has revealed the presence of genes apparently encoding a lantibiotic, designated Bsa (bacteriocin of Staphylococcus aureus), among clinical isolates of S. aureus and those associated with community-acquired methicillin-resistant S. aureus (MRSA) infections in particular. Here, we establish for the first time, through a combination of reverse genetics, mass spectrometry, and mutagenesis, that these genes encode a functional lantibiotic. We also reveal that Bsa is identical to the previously identified bacteriocin staphylococcin Au-26, produced by an S. aureus strain of vaginal origin. Our examination of MRSA isolates that produce the Panton-Valentine leukocidin demonstrates that many community-acquired S. aureus strains, and representatives of ST8 and ST80 in particular, are producers of Bsa. While possession of Bsa immunity genes does not significantly enhance resistance to the related lantibiotic gallidermin, the broad antimicrobial spectrum of Bsa strongly indicates that production of this bacteriocin confers a competitive ecological advantage on community-acquired S. aureus.
authors.affiliation: Department of Microbiology, University College Cork, Cork, Ireland.
authors.forename: Karen M
authors.initials: KM
authors.lastname: Daly
authors.forename: Mathew
authors.initials: M
authors.lastname: Upton
authors.forename: Stephanie K
authors.initials: SK
authors.lastname: Sandiford
authors.forename: Lorraine A
authors.initials: LA
authors.lastname: Draper
authors.forename: Philip A
authors.initials: PA
authors.lastname: Wescombe
authors.forename: Ralph W
authors.initials: RW
authors.lastname: Jack
authors.forename: Paula M
authors.initials: PM
authors.lastname: O'Connor
authors.forename: Angela
authors.initials: A
authors.lastname: Rossney
authors.forename: Friedrich
authors.initials: F
authors.lastname: Götz
authors.forename: Colin
authors.initials: C
authors.lastname: Hill
authors.forename: Paul D
authors.initials: PD
authors.lastname: Cotter
authors.forename: R Paul
authors.initials: RP
authors.lastname: Ross
authors.forename: John R
authors.initials: JR
authors.lastname: Tagg
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001430:Bacteriocins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D017714:Community-Acquired Infections / Q000382:microbiology*; D005827:Genetics, Microbial / Q000379:methods; D006801:Humans; D013058:Mass Spectrometry; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D016296:Mutagenesis; D010455:Peptides / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D010455:Peptides; C057656:gallidermin; C017724:staphylococcin