DUAL MRSA COVERAGE FOR NECROTIZING PNEUMONIA IN A CRITICAL CARE PATIENT

Abstract

SESSION TITLE: Monday Fellow Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the common causes of health care-associated pneumonia. Choice of antibacterial therapy can affect outcome. Vancomycin continues to remain the drug of choice for MRSA. Persistent MRSA (pMRSA) pneumonia has been described however the role of dual antimicrobial coverage for MRSA is not well known. Here, we present a case of pMRSA pneumonia that failed initial treatment with vancomycin followed by linezolid but improved with dual treatment consisting of vancomycin and ceftaroline. CASE PRESENTATION: 52-year-old male with PMHx of chronic back pain with recent lumbar spine surgery and history of opioid dependence presented with altered mental status, acute hypoxemic respiratory failure and shock. Initial Labs showed a wbc 9 with 80% left shift. CXR was consistent with pneumonia with a dense right basilar opacity. He was empirically started on vancomycin and zosyn given recent health care exposure. Respiratory culture (RC) grew MRSA and pan sensitive enterobacter; despite appropriate weight based dosing, vancomycin levels remained slightly subtherapeutic so antibiotics were switched to linezolid and ceftriaxone. He improved clinically and was extubated. 3 days after completion of 2 weeks of appropriate antibiotic therapy, he again decompensated requiring intubation and vasopressors. Meropenem and vancomycin were empirically administered. Repeat RC again grew MRSA, vancomycin minimum inhibitory concentration (MIC) DISCUSSION: MRSA is defined as an oxallicin MIC ≥4 mcg/ml. In the United States, about 7% of patients are colonized with MRSA. Vancomycin is the mainstream treatment for MRSA pneumonia. PMRSA pneumonia has not been well described and the role of dual antimicrobial coverage is not well known. In vitro synergy between vancomycin and ceftaroline has been reported in some studies but clinical experience with this therapy is limited. Our patient failed vancomycin followed by linezolid therapy. He improved rapidly with combination therapy. CONCLUSIONS: Further study is needed for the role of dual antimicrobial coverage for pMRSA. Reference #1: Gritsenko, Diana, et al. “Combination Therapy With Vancomycin and Ceftaroline for Refractory Methicillin-Resistant Staphylococcus Aureus Bacteremia: A Case Series.” Clinical Therapeutics, vol. 39, no. 1, 2017, pp. 212–218., https://doi.org/10.1016/j.clinthera.2016.12.005. Reference #2: Katie E. Barber, Michael J. Rybak, George Sakoulas; Vancomycin plus ceftaroline shows potent in vitrosynergy and was successfully utilized to clear persistent daptomycin-non-susceptible MRSA bacteraemia, Journal of Antimicrobial Chemotherapy, Volume 70, Issue 1, 1 January 2015, Pages 311–313 Reference #3: Choo, Eun Ju and Henry F Chambers. “Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia” Infection & chemotherapy vol. 48,4 (2016): 267-273. DISCLOSURES: No relevant relationships by Obed Adarkwah, source=Web Response No relevant relationships by Mona Alipour, source=Web Response No relevant relationships by Louis Gerolemou, source=Web Response No relevant relationships by Nabil Mesiha, source=Web Response Speaker/Speaker's Bureau relationship with Allergan Please note: $20001 - $100000 Added 03/18/2019 by Joshua Rosenberg, source=Web Response, value=Honoraria No relevant relationships by jad sargi, source=Web Response