Intracellular persistence of Staphylococcus aureus small-colony variants within keratinocytes: a cause for antibiotic treatment failure in a patient with darier's disease.

Intracellular persistence assays were performed with small-colony variants (SCVs) derived from a patient with Darier's disease from whom different phenotypes and genotypes of Staphylococcus aureus were isolated over a 28-month period; the assays revealed that >100-fold more SCV cells persisted intracellularly relative to the normal phenotype. The presence of intracellular S. aureus SCVs may protect against host defenses and antibiotic therapy and thus may have contributed to this patient's very prolonged skin infection.