Cardiogenic and septic shock associated with aortic and mitral valve infective endocarditis caused by Abiotrophia Defectiva from a urinary tract infection

Abstract

Abiotrophia defectiva, also known as nutritionally variant streptococcus, is part of the normal flora of the oral cavity and urogenital and intestinal tracts and is a rare cause of infective endocarditis. It is fastidious or difficult to culture and associated with high rates of septic embolization, treatment failure and mortality. We describe an unusual presentation of infective endocarditis with severe mitral valve regurgitation due to Abiotrophia defectiva in an immunocompetent patient. After a complicated hospital course, surgical replacement of both the mitral and aortic valves was performed. We suggest that this patient likely had subacute infective endocarditis before diagnosis and treatment of her urinary tract infection, and following treatment failure, she developed life-threatening infective endocarditis. This case report highlights that patients with Abiotrophia defectiva infections are at high risk for infective endocarditis and that the clinical progression from this infection can be slow, with difficulty isolating the pathogen, which can significantly impact patient outcome.

Abiotrophia defectiva: A Rare but Critical Cause of Infective Endocarditis

“…Infections due to Abiotrophia defectiva are known to cause septic embolization and mortality [11]. Our patient's case was complicated by the presence of septic emboli in the spleen and also the presence of multiple ischemic foci in the brain.…”

“…Since these bacteria are also frequently penicillin-resistant, the American Heart Association recommends using the same treatment regime as that used for Enterococcus endocarditis, which consists of ampicillin or penicillin G in addition to gentamicin for a four to six weeks period [12]. Ceftriaxone combined with gentamycin is an alternative option [11]. This combination, involving intravenous ceftriaxone and gentamicin was successfully used to treat our patient.…”

Pyridoxine-Deficient Streptococcus: An Uncommon Virulent Cause of Subacute Destructive Aortic Valve Endocarditis

“…Fortunately, for our patient, this virulent organism was quickly identified and successfully treated despite a treatment failure rate of 41%, high recurrence rate of 17%, and mortality of more than 17%. This is often attributed to delays in identification and high prevalence of beta-lactams and macrolide antibiotic resistance despite the efficacy of antibiotics in vitro [3][4][5][6][7]. The high virulence of NVS is attributed to exopolysaccharide production and the affinity to fibronectin [8].…”

“…NVS is very fastidious and will grow only on supplemented media or enriched chocolate agar [9]. In persistent blood culture-negative cases with high clinical suspicion and/or imaging supporting the diagnosis, 16S ribosomal RNA (rRNA) gene sequencing technology or matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) can be used to identify the organism [3][4][5][6][7]10].…”

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

“… A. defectiva is associated with septic embolization, but isolated de novo peripheral infections have also occurred. Cases of sepsis, osteomyelitis, brain abscess, pancreatic abscess and septic arthritis have also been reported [ 8 ].…”