title: Genetic complexity of fusidic acid-resistant small colony variants (SCV) in Staphylococcus aureus.
abstract: FusE mutants are fusidic acid-resistant small colony variants (SCVs) of Staphylococcus aureus that can be selected with aminoglycosides. All FusE SCVs have mutations in rplF, encoding ribosomal protein L6. However, individual FusE mutants including some with the same mutation in rplF display auxotrophy for either hemin or menadione, suggesting that additional mutations are involved. Here we show that FusE SCVs can be divided into three genetic sub-groups and that some carry an additional mutation, in one of the genes required for hemin biosynthesis, or in one of the genes required for menadione biosynthesis. Reversion analysis and genome sequencing support the hypothesis that these combinations of mutations in the rplF, hem, and/or men genes can account for the SCV and auxotrophic phenotypes of FusE mutants.
authors.affiliation: Uppsala University, Department of Cell and Molecular Biology, The Biomedical Center, Uppsala, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Lannergård
authors.forename: Sha
authors.initials: S
authors.lastname: Cao
authors.forename: Tobias
authors.initials: T
authors.lastname: Norström
authors.forename: Alejandro
authors.initials: A
authors.lastname: Delgado
authors.forename: John E
authors.initials: JE
authors.lastname: Gustafson
authors.forename: Diarmaid
authors.initials: D
authors.lastname: Hughes
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015169:Colony Count, Microbial; D003470:Culture Media / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000235:genetics*; D005672:Fusidic Acid / Q000494:pharmacology*; D006427:Hemin / Q000494:pharmacology; D007612:Kanamycin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D013211:Staphylococcus aureus / Q000166:cytology / Q000187:drug effects* / Q000235:genetics* / Q000254:growth & development; D024483:Vitamin K 3 / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D007612:Kanamycin; D005672:Fusidic Acid; D024483:Vitamin K 3; D006427:Hemin