Successful Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia with Ceftaroline Fosamil

Abstract

Objectives: To describe a case of successful treatment of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia with ceftaroline fosamil after failure with vancomycin and daptomycin.

Case summary: A 53-year-old female with a past medical history of cancer (unknown source/type) and hypothyroidism was admitted to the hospital with cervical and paravertebral abscess with suspected sepsis. In the emergency department (ED), magnetic resonance imaging (MRI) revealed possible spinal abscess and narrowing of the spinal canal. The patient was initiated on vancomycin 1,250 mg (~15 mg/kg) every 12 hours and cefepime 2 g every 8 hours empirically. On hospital day 4, blood and wound cultures revealed MRSA susceptible to vancomycin, but with a vancomycin minimum inhibitory concentration (MIC) of 2. Repeat blood cultures were also positive on hospital days 2 and 4. Per infectious disease team consult, therapy was converted to daptomycin 8 mg/kg/day. Although the patient responded well, acute kidney injury (AKI) on hospital day 15 prompted a change in therapy to ceftaroline fosamil 400 mg intravenous every 8 hours. For the remainder of the hospital stay, blood cultures were negative and white blood cell count was within normal limits. On day 20, the patient was discharged to a long-term care facility for continued ceftaroline treatment.

Discussion: The management of MRSA bacteremia remains challenging due to increasing antimicrobial resistance. Although the standard therapy for serious MRSA infections is vancomycin, treatment failures are becoming common in clinical practice due to increasing MICs (≥2 μg/mL). Other therapies may include daptomycin and off-label treatment with telavancin, quinupristin/dalfopristin, or ceftaroline fosamil. This report describes a patient with paravertebral abscess and MRSA bacteremia failing 3 days of vancomycin therapy due to MIC greater than or equal to 2 μg/mL and persistent bacteremia. Treatment with ceftaroline fosamil was well tolerated and resulted in continued clinical improvement. Based on this case report, ceftaroline fosamil may be a reasonable alternative for invasive MRSA infections.

Conclusions: This case report describes successful treatment of MRSA bacteremia with ceftaroline in a patient who responded poorly to conventional therapy, specifically vancomycin due to an elevated MIC (2 μg/mL).

Keywords: bactermia; ceftaroline; methicillin-resistant Staphylococcus aureus.