Pacemaker Lead Infection and Vertebral Osteomyelitis Presumed Due to Cardiobacterium hominis

Abstract

Cardiobacterium hominis is a member of the HACEK (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella) group of fastidious, gram-negative, aerobic bacilli, which are rare causes of endocarditis. The presence of C. hominis in the blood is virtually diagnostic of endocarditis, and extracardiac infections caused by C. hominis have been reported only twice [1, 2]. We describe a patient with two unique features of C. hominis bactermia: pacemaker lead infection and osteomyelitis.A 76-year-old woman was admitted to the MetroWest Medical Center (Framingham, MA) because of fever and lower back pain. These symptoms began ú2 months earlier and had led to an evaluation at another hospital. Findings on a bone scan and CT of the Figure 1. CT scan of the lumbar spine of a 76-year-old woman lumbar spine were abnormal, but were interpreted as consistent with with pacemaker lead infection and vertebral osteomyelitis (presumed degenerative changes. Cultures of blood obtained on admission were due to Cardiobacterium hominis) showing destruction of the fifth negative, and the fever subsided. One week later, the fever recurred lumbar vertebra. and a CT scan of the lumbar spine revealed narrowing of the joint space between L4 and L5 with erosion of the superior end-plate of L5 (figure 1). Two blood cultures were negative. A biopsy of the Vertebral osteomyelitis should always be suspected when palumbar spine was obtained under CT guidance, and histopathologic tients present with fever, back pain, and vertebral tenderness. evaluation was nondiagnostic; cultures of the biopsy specimen wereImaging studies are important in attaining the diagnosis [3]; in negative. A chest radiograph revealed an infiltrate. Intravenous cefuroour patient, the CT scan was virtually diagnostic of spine infecxime was administered, and the patient became afebrile. tion and diskitis. Although the culture of the bone biopsy speciOne month later, the back pain worsened and the fever recurred.men was negative, the sensitivity of a biopsy specimen evaluaBlood was drawn for culture and 10 days later the laboratory tion and the diagnosis of vertebral osteomyelitis may be as low reported that the culture yielded gram-negative rods. Additional as 25% [4]. Because C. hominis is fastidious, it is not surprising blood was obtained for cultures, and the patient was admitted to that the culture was negative. The delay in making the diagnosis the hospital for further evaluation. At the time of the admission, in our case is not unusual in patients with infections due to the patient was complaining of back pain that radiated to the lower C. hominis [1]. Factors that contribute to the diagnostic diffiabdomen and both thighs, and she gave a history of a recent 22-culties associated with this condition include the slow growth pound weight loss. The medical history was remarkable for diabeof C. hominis, inadequate duration of culture incubation, and tes mellitus, coronary artery disease, and placement of a dualprior antibiotic therapy. chamber cardiac pacemaker for...

Cardiobacterium hominis and Cardiobacterium valvarum: Two Case Stories with Infective Episodes in Pacemaker Treated Patients

“…The cases illustrate the importance of a careful echocardiographic examination giving the possibility of not having to remove the pacemaker device unnecessarily. However, though there are some reports of treatment only with antibiotics, which have been curative, most patients suffer an infective exacerbation with bacteremia, and severe complications necessitating surgical removal of the entire pacing system for cure, as in the second episode of case 1 [2, 3, 8]. This may be the result of biofilm production complicating eradication by antibiotics [9].…”

Direct Detection of Cardiobacterium hominis in Serum from a Patient with Infective Endocarditis by Broad-Range Bacterial PCR

“…Since then, fewer than 70 cases of C. hominis endocarditis have been reported in the literature. In addition, it is unusual for this organism to cause focal infections outside the vascular system, including bacterial meningitis, abdominal abscess, osteomyelitis, pericarditis, and septic arthritis (1,7,12,17). In most of the cases of infective endocarditis caused by C. hominis, there is some form of preexisting cardiac disease and a history of dental manipulation, although for most cases no portal for entry can be identified (23).…”

Pericarditis bacteriana por Cardiobacterium hominis: un caso clínico inusual

“…Otras localizaciones descritas fuera del sistema circulatorio, habitualmente como una localización secundaria por vía vascular, incluyen meningitis 16 , abscesos abdominales 17 y osteomielitis 18 . Siendo parte de la microbiota orofaríngea 5 de la mayoría de los individuos (70%), donde es descrito como avirulento , los inóculos de más de 10 9 microorganismos no evidencian infección en animales de experimentación 19 ; sin embargo, pacientes bacteriémicos y con daño valvular o prótesis valvulares cardíacas pueden desarrollar endocarditis.…”