Case Report: A rare case of prosthetic valve infective endocarditis caused by Aerococcus urinae [version 1; peer review: 2 approved with reservations]

Infective endocarditis (IE) is a serious and life threatening cardiac condition, most commonly caused by staphylococci, streptococci, enterococci and rarely by HACEK organisms ( Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella corrodens and Kingella). Here, we present a case of IE caused by Aerococcus urinae in a 75-year-old man with a bioprosthetic aortic valve. Aerococcus urinae is a gram-positive, catalase negative microorganism, and is usually an isolate of complicated urinary tract infections in the elderly male population. It is associated with high morbidity and mortality. Awareness of this organism as a cause of IE is important, since failure to recognize the condition may lead to adverse clinical outcomes and significant complications with even fatal outcome, as in this case.