2019 Volume 68 Issue 1 Pages 186-191
We report a case of fatal endocarditis caused by Aerococcus urinae isolated by blood culture, which was timely identified by MALDI Biotyper. A seventy-year-old male with chronic cystitis and aortic valve replacement was admitted to our hospital for suspected urinary tract infection. By blood culture on admission, we isolated a gram-positive coccus that grew in clusters and produced alpha-hemolysis on blood agar. The result of analysis by MALDI Biotyper indicated A. urinae. He died on the 26th hospital day complicated by cardiogenic brain infarction. A. urinae is an aerobic gram-positive coccus that appears in cluster form on gram staining and grows as an alpha-hemolysis colony on blood agar. Thus, it could be misidentified as alpha-hemolytic streptococci and staphylococci. Previous reports indicate that A. urinae is associated with urinary tract infection and bacteremia. It should be emphasized that it potentially causes serious infective endocarditis.
