Infective endocarditis due to Abiotrophia defectiva and its feared complications in an immunocompetent person: Rare, but real

Abstract

Abiotrophia defectiva is nutritional deficient streptococci that cannot be cultured on routine culture medias. Even though fastidious in growth requirement, it is a virulent bacterium preferentially affecting endovascular structures and is implicated in many culture-negative endocarditis cases. Unlike other organisms, it is known for heart valve destruction leading to heart failure and excessive embolization rates. It's inherent resistance to routinely used antibiotics also contributed to increased mortality and morbidity in affected individuals and warrants timely diagnosis and prompt treatment. Our patient, a previous healthy individual, acquired this rare bacterium from intravenous drug abuse and developed infective endocarditis with valve destruction, heart failure, and distal embolization to multiple organs. He underwent multiple surgeries including mitral valve replacement and embolectomy with clinical improvement. Our case reiterates the possibility of rare cause of common diseases and raises awareness of infective endocarditis caused by A. defectiva among medical professionals.

Abiotrophia defectiva: A Rare but Critical Cause of Infective Endocarditis

“…Abiotrophia defectiva is a part of the normal flora of the oral cavity, the urogenital and the intestinal tracts [4]. Immunosuppression, pregnancy, and prosthetic valves are the common predisposing factors for this rare infection [5]. In one of the first reported cases of endocarditis due to Abiotrophia defectiva in Korea, the patient who was on post-mitral valve replacement (MVR) had developed the infection following a tooth extraction and was treated successfully with appropriate antibiotics and a second MVR [2].…”

“…Molecular biology technicals allow quicker diagnosis, which can lead to better prognosis [8]. Suspicion regarding this organism should arise in cases of culturenegative endocarditis and additional testing with supplemented media should be performed to encourage growth of colonies [5,9]. A.defective is a pleomorphic organism, appearing as Grampositive cocci, coccobacilli, and bacilli forms depending on the culture media [10].…”

Infective endocarditis case due to <i>Abiotrophia defectiva</i> concurrent with septic embolism and acute coronary syndrome

“…A. defectiva üremesi için gerekli olan pridoksin, L-sistein, ve diğer gerekli besin maddelerini sentezleyemediğinden diğer bakterilere gereksinim duyar veya bu maddeleri içeren zenginleştirilmiş besiyerinde ürer. Gram pozitif pleomorfik kok veya kokobasil şeklinde olup, otomatize kan kültür sistemlerinde saptanmasına rağmen, pridoksin ve sisteinle zenginleştirilmiş çikolata agar dışındaki besiyerlerinde üremez [6].…”

“…Kalp yetmezliği ile sonuçlanan kapak destrüksiyonu ve yaygın embolizasyon oranı yüksektir. A. defectiva'nın etken olduğu endokarditin mortalite ve morbidite oranı yüksek olduğundan erken tanı ve tedavisi gerekir [6] . Rudrappa Sonuç olarak, nadir de olsa A. defectiva gibi nadir görülen bakterilerin de enfektif endokardit etkeni olabileceği, septik embolilere bağlı akut koroner sendrom ve organ enfarktüsleri gibi komplikasyonlarla birlikte görülebileceği akılda tutulmalıdır.…”

Abiotrophia defectiva endophthalmitis following routine cataract surgery: the first reported case in the United Kingdom

“…Difficult to cultivate, it is highly virulent and can affect endovascular structures. It has subsequently been identified as the cause of numerous culture-negative endocarditis cases, including in immunocompetent patients [ 6 ], some with recent history of dental treatment [ 7 ]. A. defectiva is associated with septic embolization, but isolated de novo peripheral infections have also occurred.…”