BACKGROUND: Initially presumed as nonpathogenic, the bacterial genus aerococcus now includes 7 distinct virulent and avirulent species. Aerococcus urinae first isolated in 1992 is an uncommon cause of urinary tract infection (UTI) and is seen in only 0.15% to 0.8% of cases. A. urinae associated invasive bacteremia and systemic infection are extremely rare entities. Less than 50 cases of A. urinae associated with infective endocarditis (IE) have been reported in the literature, with the prevalence being 3 per 1 million.

CASE REPORT: A 59-year-old male presented to our hospital with exertional dyspnea and new-onset atrial flutter. Prior to his current admission patient was treated for A. urinae associated UTI with levofloxacin for 10 days. A transthoracic echocardiogram revealed severe aortic regurgitation with aortic valve endocarditis, which was subsequently confirmed on transesophageal echocardiogram. Blood cultures displayed gram-positive cocci in clusters, ultimately identified as A. urinae. The patient was treated with intravenous vancomycin and underwent surgical aortic valve replacement along with patch repair for underlying aortic wall ulcer.

CONCLUSIONS: To the best of our knowledge, this is the first-ever reported case of A. urinae associated IE complicated by an aortic wall ulcer. Male gender, age >65 years, and preexisting urinary tract pathology have all been implicated as risk factors for aerococcus infection. A. urinae is almost always sensitive to penicillin, carbapenem, and aminoglycosides.

Keywords: Aerococcus, Aortic Diseases, Aortic Valve Insufficiency, Endocarditis, Aortic Valve, Atrial Fibrillation, Dyspnea, Echocardiography, Echocardiography, Transesophageal, Risk Factors, Ulcer