OS-MRSA Genome Sequencing

Phenotypic and genomic characteristic of oxacillin-susceptible mecA-positive Staphylococcus aureus. Staphylococcus aureus harboring mecA but susceptible to oxacillin (oxacillin-susceptible MRSA, OS-MRSA) are recognized as difficult-to-detect pathogens. Collection of OS-MRSA clinical isolates was studied. Mutations in the promoter region and a low level of mecA expression are probably the reasons for the low level of beta-lactam resistance in OS-MRSA. The OS-MRSA phenotype (false susceptibility to beta-lactams) may be the reason for the mis-prescription of beta-lactams for the treatment of staphylococcal infections.