Optimized In Vitro Antibiotic Susceptibility Testing Method for Small-Colony Variant Staphylococcus aureus

Optimized In Vitro Antibiotic Susceptibility Testing Method for Small-Colony Variant Staphylococcus aureus.

Staphylococcus aureus small-colony variants (SCVs) emerge frequently during chronic infections and are often associated with worse disease outcomes. There are no standardized methods for SCV antibiotic susceptibility testing (AST) due to poor growth and reversion to normal-colony (NC) phenotypes on standard media. We sought to identify reproducible methods for AST of S. aureus SCVs and to deter...

Small colony variants in Staphylococcus aureus and other species: antibiotic selection, antimicrobial susceptibility, and biofilm formation

Antibiotic susceptibility of community-acquired Staphylococcus aureus.

55% of a sample of patients in a rural community, and 76% of a sample of patients and staff in the local district hospital were found to be nasal carriers for Staphylococcus aureus. The in vitro antibiotic susceptibility patterns of 46 strains of S. aureus isolated in nasal carriers as well as of 43 strains in community-acquired skin infections were characterised. High levels of resistance were...

Alternative Evolutionary Pathways for Drug-Resistant Small Colony Variant Mutants in Staphylococcus aureus

Staphylococcus aureus is known to generate small colony variants (SCVs) that are resistant to aminoglycoside antibiotics and can cause persistent and recurrent infections. The SCV phenotype is unstable, and compensatory mutations lead to restored growth, usually with loss of resistance. However, the evolution of improved growth, by mechanisms that avoid loss of antibiotic resistance, is very po...

Small-colony variants of Staphylococcus aureus.

Staphylococcus aureus remains a versatile and dangerous pathogen. Small-colony variants (SCVs) of S. aureus are a naturally occurring sub-population, first described nearly 100 years ago. These variants, of which there are different classes, grow slowly and have many atypical characteristics thought to be due to defective electron transport, and include minute colony forms. SCVs have been isola...