Clinical Isolates of <i>Staphylococcus aureus</i> with Ribosomal Mutations Conferring Resistance to Macrolides

Abstract

Six strains of Staphylococcus aureus isolated from cystic fibrosis patients after treatment with azithromycin were cross-resistant to azithromycin and erythromycin. None of the isolates contained erm or msr(A) genes, but they all carried either A2058G/U or A2059G mutations within the rrl genes, with a majority of the rRNA copies bearing the mutation. One strain displayed an additional mutation in the rplV gene, encoding the L22 ribosomal protein.