Serratia marcescens Prosthetic Valve Endocarditis: Portending a Dismal Course

<i>Serratia marcescens,</i> an opportunist pathogen mainly isolated in healthcare-associated infections, is a rare cause of infective endocarditis (IE) that generates an increased mortality rate compared to the usual agents. We report a case of a 70-year-old male patient who underwent a mitral valve replacement and was readmitted two months later with a high-grade continuous fever and deterioration of the general status. The diagnosis of early IE due to <i>S. marcescens</i> was established upon further investigation. The patient was treated with ertapenem and underwent surgery. Nevertheless, the prognosis was not favorable. Due to the rarity of similar presentations and the grim prognosis that <i>S. marcescens</i> IE portends, further investigation on this subject is warranted. This can aid in preventing future occurrences and help issue guidelines for therapeutic management, especially in patients with prosthetic valves.