Infective endocarditis caused by Abiotrophia defectiva presenting as anterior mitral leaflet perforation mimicking cleft anterior mitral leaflet

Abiotrophia defectiva Endocarditis: A Rare Cause with Aggressive Systemic Embolisation and Need of Valve Replacement

Infective endocarditis (IE) is a well-described infectious disease, one with increased morbidity and mortality being the third or fourth most common life-threatening infection syndrome. Abiotrophia defectiva is a non-motile, catalase negative, gram-positive coccus in a chain, which can be isolated from the oral cavity, intestinal, and genitourinary tracts. IE due to this agent is rare and associated with heart valve destruction, congestive heart failure, and high embolisation rates, these being the major mortality causes. We present a case of IE due to this agent, complicated with a stroke, and splenic and renal infarction, with the need for aortic valve replacement. This article highlights the gaps of knowledge left by the rarity of this disease, which range from its diagnosis to its treatment, and what we need to mitigate such gaps, supported with a case description of a successful treatment of this infection.

LEARNING POINTS

Infective endocarditis due to Abiotrophia defectiva has usually an indolent course, but the embolisation potential is very high.The major causes of mortality with this species are congestive heart failure due to valve destruction and the presence of multiple emboli.Surgical intervention rates are high with Abiotrophia defectiva, reaching 50% of cases.

Abiotrophia Defectiva as a Rare Cause of Mitral Valve Infective Endocarditis With Mesenteric Arterial Branch Pseudoaneurysm, Splenic Infarction, and Renal Infarction: A Case Report

Introduction

Abiotrophia defectiva (A. defectiva) is a rare species leading to infective endocarditis (IE) with a poor prognosis. We describe a previously healthy patient with mitral valve infective endocarditis caused by A. defectiva.

Case report

A young man was admitted with intermittent fever. Echocardiography confirmed vegetation on the mitral valve with evidence of valve perforation and severe mitral regurgitation. Three sets of blood cultures became positive for A. defectiva. As he presented with manifestations of mesenteric arterial branch pseudoaneurysm, splenic and renal infarction, mitral valve replacement, and embolization of superior mesenteric aneurysm were operated during 8 weeks' targeted antibiotic therapy.

Conclusion

This case study emphasizes the importance of considering A. defectiva as a rare but important cause of IE and of performing blood culture to make its accurate diagnosis and timely anti-infective treatment. Early surgical management and active prevention of complications have been associated with a favorable prognosis.

Abiotrophia defectiva Infective Endocarditis: A Rare and Dangerous Cause of Endocarditis

Infective endocarditis is an uncommon heart infection, typically involving heart valves. Abiotrophia defectiva is a rare cause of endocarditis, typically found within the GI tract, and is usually difficult to isolate and requires specialized media. We report a case of Abiotrophia defectiva endocarditis following a root canal.

Case Report: Report of Infective Endocarditis Caused by Abiotrophia defectiva and Literature Review

OBJECTIVE

To report the clinical features of the first child with infective endocarditis (IE) caused by Abiotrophia defectiva in mainland China and to raise awareness of the disease.

METHODS

The clinical data of a child with IE caused by A. defectiva admitted to Xi'an Children's Hospital in July 2021 were collected, and the relevant literature was reviewed.

RESULTS

The child was a female, 8 years old, admitted with fever for 4 days and right-sided limb weakness for 3 days. The illness started with suppurative tonsillitis, followed by headache, fatigue, right-sided mouth, slurred speech, right limb weakness, and unstable holding. Transthoracic echocardiography showed that the mitral valve vegetation was formed and vegetation could also be seen at the entrance of the pulmonary vein at the posterior wall of the left atrium. Cranial contrast-enhanced MRI + magnetic resonance angiography showed multiple intracranial pseudoaneurysm formation and pontine infarction. After A. defectiva was detected by metagenomic next-generation sequencing (mNGS) in cerebrospinal fluid and blood detected, the infection was controlled by anti-infective treatment with meropenem and vancomycin. On the 36th day after admission, due to severe headache and slurred speech, the head CT showed hemorrhage of right parietal pseudoaneurysm and cerebral sickle hernia, and right temporo-occipital hematoma evacuation, cerebrovascular malformation resection, and cranial decompression were performed immediately. After the surgery, her speech ability gradually recovered, the muscle strength of her left upper limb was about grade III, while the muscle strength of the rest of the limbs was normal. After a total of 60 days of hospitalization, her family requested to be discharged.

CONCLUSION

This pediatric patient is the first case of childhood IE caused by A. defectiva in mainland China, and the first time in the world that A. defectiva was detected by mNGS in patients with IE.

An infrequent etiology of Infective Endocarditis

Abiotrophia. defectiva is an infrequent but an important cause of infectious endocarditis (IE). IE caused by A. defectiva may actually be more common than what is reported in the literature because of its failure to grown on routine media like blood agar and MacConkey agar, besides difficulty in its identification by conventional methods. IE by A. defectiva generally have more fulminant course and is associated with higher mortality and morbidity due to frequent embolic episodes and valvular tissue destruction. Ceftriaxone or vancomycin in combination with gentamicin and surgical replacement of valve is the recommended management.

Abiotrophia defectiva as a Rare Causative Agent of Periprosthetic Total Knee Arthroplasty Infections: A Case Report and Literature Review

We present a case of Abiotrophia defectiva in a prosthetic knee infection following total knee replacement for the first time. A 69-year-old female was prediagnosed with prosthetic knee infection, and a two-stage revision arthroplasty was applied. A. defectiva was cultured by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) from the synovial fluid aspirates. Penicillin G and gentamicin had been administered. One year postoperatively, a scintigraphy showed no recurrence. A. defectiva may be missed in culture negative patients with knee or hip arthroplasty. They should be carefully evaluated if they have undergone recent dental procedures.