Staphylococcus Aureus Bacteremia Antibiotic Treatment Options

Inclusion Criteria: * Age at least 18 years * Not legally incapacitated * Written informed consent from the trial subject has been obtained * Blood culture positive for S. aureus not considered to represent contamination * At least one negative follow-up blood culture obtained within 24-96 hours after the start of adequate antimicrobial therapy to rule out persistent bacteremia and Absence of a blood culture positive for S. aureus at the same time or thereafter. * Five to seven full days of appropriate i.v. antimicrobial therapy administered prior to randomization documented in the patient Chart. Appropriate therapy has all of the following characteristics: 1. Antimicrobial therapy has to be initiated within 72h after the first positive blood culture was drawn. 2. Provided in-vitro susceptibility and adequate dosing (as judged by the PI) preferred agents for pre-randomization antimicrobial therapy are flucloxacillin, cloxacillin, vancomycin and daptomycin. However, the following antimicrobials are allowed: * MSSR: penicillinase-resistant penicillins (e.g. flucloxacillin, cloxacillin), β-lactam plus β-lactamase-inhibitors (e.g. ampicillin+sulbactam, piperacillin+tazobactam), cephalosporins (except ceftazidime), carbapenems, clindamycin, fluoroquinolones, trimethoprimsulfamethoxazole, doxycycline, tigecycline, vancomycin, teicoplanin, telavancin, linezolid, daptomycin, ceftaroline, ceftobiprole, and macrolides. * MRSA: vancomycin, teicoplanin, telavancin, fluoroquinolones, clindamycin, trimethoprim-sulfamethoxazole, doxycycline, tigecycline, linezolid, daptomycin, macrolides, ceftaroline, and ceftobiprole. Exclusion Criteria: * Polymicrobial bloodstream infection, defined as isolation of pathogens other than S. aureus from a blood culture obtained in the time from two days prior to the first positive blood culture with S. aureus until randomization. Common skin contaminants (coagulase-negative staphylococci, diphtheroids, Bacillus spp., and Propionibacterium spp.) detected in one of several blood cultures will not be considered to represent polymicrobial infection * Recent history (within 3 months) of prior S. aureus bloodstream infection * In vitro resistance of S. aureus to all oral or all i.v. study drugs * Contraindications for all oral or all i.v. study drugs * Previously planned Treatment with active drug against S. aureus during Intervention Phase (e.g. cotrimoxazol prophylaxis) * Signs and symptoms of complicated SAB as judged by an ID physician. Complicated infection is defined as at least one of the following: * deep-seated focus: e.g. endocarditis, pneumonia, undrained abscess, empyema, and Osteomyelitis * septic shock, as defined by the AACP criteria (23), within 4 days before randomization * prolonged bacteremia: positive follow-up blood culture more than 72h after the start of adequate antimicrobial therapy * body temperature \>38 °C on two separate days within 48h before randomization * Presence of the following non-removable foreign bodies (if not removed 2 days or more before randomization): * prosthetic heart valve * deep-seated vascular graft with foreign material (e.g. PTFE or dacron graft). Hemodialysis shunts are not considered deep-seated vascular grafts. * ventriculo-atrial shunt * Presence of a prosthetic joint (if not removed 2 days or more before randomization). This is not an exclusion criterion, if all of the following conditions are fulfilled: * prosthetic joint was implanted at least 6 months prior, and * catheter-related infection, skin and soft tissue infection, or surgical wound infection is present (as defined below), and * joint infection unlikely (no clinical or imaging signs) * Presence of a pacemaker or an automated implantable cardioverter Defibrillator (AICD) device (if not removed 2 days or more before randomization). This is not an exclusion criterion, if all of the following conditions are fulfilled: * pacemaker or AICD was implanted at least 6 months prior, and * catheter-related infection, skin and soft tissue infection, or surgical wound infection is present (as defined below), and * no clinical signs of infective endocarditis, and * infective endocarditis unlikely by echocardiography (preferably TEE), and * pocket infection unlikely (no clinical or imaging signs) * Failure to remove any intravascular catheter which was present when first positive blood culture was drawn within 4 days of the first positive blood culture * Severe liver disease. This is not an exclusion criterion, if the following condition is fulfilled: \- catheter-related infection, skin and soft tissue infection, or surgical wound infection is present * End-stage renal disease. This is not an exclusion criterion, if all of the following conditions are fulfilled: * catheter-related infection, skin and soft tissue infection, or surgical wound infection is present (as defined below), and * no clinical signs of infective endocarditis, and * infective endocarditis unlikely by echocardiography (preferably TEE), and * in patients with a hemodialysis shunt with a non-removable foreign body (e.g. synthetic PTFE loop): no clinical signs of a shunt infection * Severe immunodeficiency * primary immunodeficiency disorders * neutropenia (\<500 neutrophils/μl) at randomization or neutropenia expected during intervention phase due to immunosuppressive treatment * uncontrolled disease in HIV-positive patients * high-dose steroid therapy (\>1 mg/kg prednisone or equivalent doses given for \>4 weeks or planned during intervention) * immunosuppressive combination therapy with two or more drugs with different mode of action * hematopoietic stem cell transplantation within the past 6 months or planned during treatment period * solid organ transplant * treatment with biologicals within the previous year * Life expectancy \< 3 months * Inability to take oral drugs * Injection drug user * Expected low compliance with drug regimen * Participation in other interventional trials within the previous three months or ongoing * Pregnant women and nursing mothers * For premenopausal women: Failure to use highly-effective contraceptive methods for 1 month after receiving study drug. The following contraceptive methods with a Pearl Index lower than 1% are regarded as highly-effective: * oral hormonal contraception ('pill') * dermal hormonal contraception * vaginal hormonal contraception (NuvaRing®) * contraceptive plaster * long-acting injectable contraceptives * implants that release progesterone (Implanon®) * tubal ligation (female sterilisation) * intrauterine devices that release hormones (hormone spiral) * double barrier methods * Persons with any kind of dependency on the investigator or employed by the sponsor or investigator * Persons held in an institution by legal or official order