Infective Endocarditis Due to Corynebacterium Species: Clinical Features and Antibiotic Resistance

Abstract

Background: Corynebacterium species are often dismissed as contaminants in blood cultures, but they can also cause infective endocarditis (IE), which is a severe condition. Antibiotic resistance of corynebacteria is increasing making treatment challenging. Reports on IE caused by Corynebacterium species are scarce and more knowledge is needed. Methods: Cases of IE caused by Corynebacterium species were identified through the Swedish Registry of Infective Endocarditis. Isolates were collected for species redetermination by matrix-assisted laser desorption ionization-time of flight and for antibiotic susceptibility testing using Etests. Results: Thirty episodes of IE due to Corynebacterium species were identified between 2008 and 2017. The median age of patients was 71 years (interquartile range, 60-76) and 77% were male. Corynebacterium striatum (n = 11) was the most common IE causing pathogen followed by Corynebacterium jeikeium (n = 5). Surgery was performed in 50% and in-hospital mortality rate was 13%. Patients with IE caused by Corynebacterium species were significantly more likely to have prosthetic valve endocarditis (70%), compared with patients with IE due to Staphylococcus aureus or non-beta-hemolytic streptococci (14% and 26%, respectively) (P