title: Molecular characterization of rpoB mutations conferring cross-resistance to rifamycins on methicillin-resistant Staphylococcus aureus.
abstract: Mutations of the rpoB gene conferring resistance to rifampin were analyzed in 40 methicillin-resistant Staphylococcus aureus isolates obtained from six countries. Interestingly, the majority of clinical isolates showed multiple mutations within rpoB. The amino acid substitution 481His-->Asn was the most prevalent one, capable of conferring low-level resistance on its own. Cross-resistance to rifampin, rifabutin, and rifapentine was demonstrated for all mutants identified. The level of resistance to rifamycins correlated with both the mutation position and type of amino acid substitution.
authors.affiliation: Institute of Medical Microbiology, University Hospital of Frankfurt, Frankfurt am Main, Germany.
authors.forename: T A
authors.initials: TA
authors.lastname: Wichelhaus
authors.forename: V
authors.initials: V
authors.lastname: Schäfer
authors.forename: V
authors.initials: V
authors.lastname: Brade
authors.forename: B
authors.initials: B
authors.lastname: Böddinghaus
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D012321:DNA-Directed RNA Polymerases; D004352:Drug Resistance, Microbial; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D005838:Genotype; D006801:Humans; D016106:Methicillin Resistance / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics*; D012294:Rifamycins / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D010940:Plant Proteins; D012294:Rifamycins; C101305:RpoB protein, Oryza sativa; D012321:DNA-Directed RNA Polymerases