Failure of combination therapy for Staphylococcus aureus bone infection: a case of in vivo selection with resistance to rifampicin and fusidic acid.

Staphylococcus aureus is one of the main etiologies of bone and device-related infections. Treatment of these orthopedic infections combines mostly rifampicin with other antibiotics. The recurrence or failure rate after fusidic acid/rifampicin treatment remains low (<10%). We discuss here a case of antibiotic treatment failure for Staphylococcus aureus bone infection with in vivo selection of rifampicin and fusidic acid resistance. We also report a new mutation in fusA gene involved in fusidic acid resistance.