Cardiobacterium valvarum, a fastidious Gram-negative bacterium, was detected in the aortic valve of a previously healthy 63-year-old man by broad-range PCR and 16S rRNA gene sequencing. In contrast to the patients in five previously published cases, our patient had neither a congenital bicuspid nor a prosthetic aortic valve. Here, we present a case of C. valvarum native tricuspid aortic valve infective endocarditis and a review of the literature.
IntroductionMembers of the genus Cardiobacterium (Cardiobacterium hominis, Cardiobacterium valvarum) are a common part of the normal human oropharyngeal flora, but they can rarely act as pathogens if the mucosal integrity is disturbed (Gatselis et al., 2006). Since the first C. hominis isolation from a patient with infective endocarditis (IE) in 1962, only 87 cases have been reported in the literature (Brouqui & Raoult, 2001; Apisarnthanarak et al., 2002;Lesimple et al., 2002;Balcou-Leroy et al., 2003;Arnold et al., 2004;Walkty, 2005;Shivaprakasha et al., 2007;Jenssen et al., 2008). C. valvarum was first described in 2004, and five cases of IE caused by this species have been published so far (Han et al., 2004;Hoover et al., 2005; Bothelo et al., 2006; Geißdörfer et al., 2007;Gonzales et al., 2007). All of these C. valvarum IE patients had some form of pre-existing cardiac disease (congenital bicuspid aortic valve in four and prosthetic aortic valve in one), while 4/5 had histories of dental manipulation or poor teeth and 3/5 were afebrile. C. valvarum was not specifically identified in blood from any of the patients, but Cardiobacterium sp. was found in 2/5, HACEK in 1/5 and a Gram-negative bacterium in 1/5. In one case, C. valvarum was identified incorrectly as Eubacterium tenue. All cultures from resected valves were negative (3/3).Here, we report a case of C. valvarum IE affecting a normal (tricuspid) aortic valve in a patient with no history of recent dental procedure that was detected by broad-range PCR and 16S rRNA gene sequencing.
Case reportA 63-year-old man was admitted to the University Hospital Brno with an approximate 1-month history of gradually developing resting breathlessness and repetitious episodes of cardiac decompensation. Chest pain, palpitation and weight loss were absent. The patient's personal history included type 2 diabetes, hypertension and cataract surgery, but no previously documented cardiac failure. He was not a drug addict and had not undergone any recent dental manipulations.On admission, his temperature was normal, his blood pressure was 96/30 mmHg and his heart rate was 90 beats min
21. An auscultation revealed both systolic and diastolic aortic murmurs and rales at the lung bases. A transoesophageal echocardiogram showed a mobile element of 2065 mm on the partially destroyed tricuspid aortic valve resulting in severe aortic valve regurgitation and mild functional mitral and tricuspid valve regurgitations. An angiogram showed no significant coronary stenosis, but right heart catheterization revealed severe lung hypertension. No oral ...
