Oxacillin plus ertapenem combination therapy leads to rapid blood culture clearance and positive outcomes among patients with persistent MSSA bacteraemia: a case series

Abstract

Background Bloodstream infections caused by MSSA are associated with significant morbidity and mortality. Traditional treatment of MSSA bacteraemia includes an IV antistaphylococcal β-lactam and surgical source control when indicated. Objectives To evaluate the time to blood culture clearance as well as in-hospital and 90 day mortality in patients with persistent MSSA bacteraemia treated with combination antistaphylococcal penicillin plus carbapenem therapy. Methods Consecutive patients with persistent MSSA bacteraemia treated with combination therapy were identified by study investigators and reviewed by independent clinicians. The decision to initiate combination therapy was made by the consulting clinician or by the institution’s multidisciplinary endocarditis team. Results Among 10 patients with a median of 5 days of persistent MSSA bacteraemia, treatment with an antistaphylococcal penicillin plus carbapenem led to sterilization of blood cultures in all patients. Blood culture clearance occurred in a median of 1 day and patients received a median of 6 days of combination treatment. Four of seven patients who underwent source control of their primary site of infection cleared their bacteraemia on combination therapy prior to the surgical intervention. All patients survived to hospital discharge and 90 days post-discharge. Conclusions These data extend prior findings and provide further evidence that suggests the potential benefits of combination therapy among patients with persistent MSSA bacteraemia.

Oxacillin plus ertapenem rapidly clears persistent left ventricular assist device-related methicillin-susceptible Staphylococcus aureus bacteremia

“…Therefore, their addition would complement the relative proclivity of cefazolin and ASP for PBP2. While oxacillin is thought to have higher affinity for PBP1, the data presented in this case report and by El-Dalati et al suggest oxacillin as a suitable agent for this salvage therapy 8 . Oxacillin may exhibit a similar mechanism for synergy with complimentary PBP-2 binding or may possibly offer more complete PBP1 saturation.…”

“…Combination treatment was initiated following 5 days of persistent bacteremia. Blood sterility was achieved in all patients; six patients had documented clearance within one day 8 . Here, oxacillin plus ertapenem was the most common regimen, suggesting that salvage combination therapy may be used with either ASP or cefazolin.…”

Management of infective endocarditis in pregnancy by a multidisciplinary team: a case series

“…Consequently, 3 patients were treated with combination beta-lactam therapy, a novel approach that has been shown to decrease time to blood culture clearance and is associated with low-mortality in patients with MSSA endocarditis. 11 , 12 Historically patients with injection drug use and/or pregnancy have high rates of patient-directed discharges and failure of antibiotic completion. 18 , 19 Encouragingly, there were no patient-directed discharges after involvement of the multidisciplinary endocarditis team.…”

Oxacillin plus ertapenem rapidly clears persistent left ventricular assist device‐related methicillin‐susceptible Staphylococcus aureus bacteremia

“…Blood sterility was achieved in all patients; six patients had documented clearance within 1 day. 7 Here, oxacillin plus ertapenem was the most common regimen, suggesting that salvage combination therapy may be used with either ASP or cefazolin. This conclusion is strengthened in our patient case.…”

“…While oxacillin is thought to have higher affinity for PBP1, the data presented in this case report and by El-Dalati et al suggest oxacillin as a suitable agent for this salvage therapy. 7 Oxacillin may exhibit a similar mechanism for synergy with complimentary PBP-2 binding or may possibly offer more complete PBP1 saturation. This combination has repeatedly demonstrated a clear and rapid resolution of persistent bacteremia.…”