Escherichia coli endocarditis of a native mitral valve

Abstract

Escherichia coli ( E.coli ) is a rare cause of endocarditis, although is a common causative agent of bacteremia. An 89-year-old woman presented with recurrent episodes of fever and persistent E. coli bacteremia with 3-month duration, despite antimicrobial therapy. At first, a urinary tract infection was diagnosed and later a mycotic aneurysm of the abdominal aorta was found and required an endovascular repair. The persistence of fever and the evidence of a systolic murmur at the mitral focus raised the suspicion of endocarditis. A transesophageal echocardiogram and a cardiac Magnetic Resonance Imaging (MRI) confirmed the presence of a vegetation at the mitral valve and the patient was treated with ceftriaxone. The presence of comorbid conditions and certain bacterial virulence factors predispose to this rare condition. A high level of suspicion is important to early diagnosis and prompt therapy.

The causal relationship between O2:K7:H6 extra-intestinal pathogenic Escherichia coli (ExPEC) and native valve endocarditis: a case report

“…Additionally, it has been shown that some co-morbidities, such as diabetes, malignancy, excessive alcohol consumption, hemodialysis could predispose to E. coli infective endocarditis [ 1 ]. Several studies have reported, that among the four heart valves, the native mitral valve seems to be the most frequently affected endocarditis caused by E. coli [ 1 , 4 – 10 ].. Here, we report a rare case of E. coli O2:K7:H6, B2, ST141 associated with urinary tract infection (UTI) and endocarditis.…”

“…Adhesins can play a key role in pathogenic process. As suggested by Nogueira et al some of these factors could enable E. coli to adhere to cardiac valves [ 4 ]. The present isolate was positive for at least two adhesins, P fimbriae ( papA _F12 and papC ) and S fimbrial/F1C fimbriae ( focC, focI, sfaD, sfaE and sfaS ) that are frequent in uropathogenic human isolates and extraintestinal avian pathogenic E. coli (APEC) isolates.…”