Hi Thanks for posting your query. I can understand your concern regarding the effectiveness of the mentioned antibiotics to eradicate the staplylococus aureus infection. Well, based on the culture and sensitivity of the white discharge the most commonly used and effective antibiotics are Flucloxacillin or Clindamycin. Metronidazole is effective in mixed bacterial infections, where as Erythromycin is less effective in the treatment of staphylococcal infections. Hope this answers your query. Consult your doctor for an appropriate course of antibiotics based on culture and sensitivity results. Wishing you a very good health.