Abiotrophia defectiva endocarditis - Diagnostic and therapeutic challenge: Case report

Abstract

Belonging to the normal oral, gastrointestinal, and urogenital flora, Abiotrophia defectiva is responsible for 1-2 % of all infective endocarditis (IE) cases. The manifestation of A.defectiva endocarditis may by atypical, without fever. Difficult to isolate pathogen requires special culture media. A 45-year-old female was admitted due to anemia and progressive weight loss (8 kg in 6 months). She had a history of benign mitral valve (MV) prolapse and non-stenotic bicuspid aortic valve (BAV). In echocardiography, large vegetations on MV and small vegetation on BAV were found. An enriched medium for fastidious pathogens was used. A. defectiva was identified using biochemical analysis with VITEK-2 Compact. In the fourth week of antibiotic therapy, she required urgent MV replacement due to MV regurgitation progression while vegetation on BAV disappeared. Although patient's frailty and underweight caused prolonged postoperative wound healing, she was transferred to rehabilitation in good conditions. No relapse of IE was observed during five-month follow-up.

Keywords: Abiotrophia defectiva; Echocardiography; Infective endocarditis; Microbiological diagnosis.

Fig. 1

Echocardiography at admission: Large vegetations on mitral valve - MV (A and B) and small vegetation on bicuspid aortic valve - BAV (C and D). TTE - transthoracic echocardiography, TEE - transesophageal echocardiography.

Fig. 2

TEE immediately before surgery: severe MV regurgitation in color doppler imaging, BAV without vegetation (A and B) and 6 months after surgery: MV bioprosthesis and BAV without vegetations (C and D).