Sepsis Caused by Elizabethkingia meningoseptica Successfully Treated by Polymyxin B: A Case Report

Introduction: Elizabethkingia meningoseptica (EM) is a non-fermenting Gram-negative bacterium that is a conditional pathogen and easily causes infection in neonates and immunocompromised patients. The infection of the bacterium is prone to develop multi-drug resistance, difficult to treat, and associated with a high mortality rate. Case Presentation: A 28-year-old female was admitted to the intensive care unit (ICU) of our hospital due to fulminant myocarditis, cardiogenic shock, acute heart failure, and multiple organ dysfunction syndrome (MODS) on 24 April 2019. The patient developed a lung infection and sepsis after admission. Two sputum culture tests on 27 April and 4 May showed infection with Pseudomonas aeruginosa and multi-drug resistance. The minimum inhibitory concentration (MIC) for imipenem was 4 mg/L and 8 mg/L, respectively. Four blood cultures on 9 May suggested an EM infection and multi-drug resistance, the MIC for imipenem was >= 16 mg/L. Due to the serious condition of the patient, imipenem-resistant lung infection, and typical sepsis manifestations, we initiated a regimen of polymyxin B combined with meropenem between 3 and 12 May. The infection was well-controlled and the patient was discharged on 14 May. Conclusions: A polymyxin B-based combinational regimen is effective in the treatment of sepsis due to EM and play an important role in controlling EM-associated mixed infections.