Septicaemia caused by Cardiobacterium hominis. A case report

Cardiobacterium hominis endocarditis: Two cases and a review of the literature

Cardiobacterium hominis, a member of the HACEK group (Haemophilus parainfluenzae, Haemophilus aphrophilus, and Haemophilus paraphrophilus, Actinobacillus actinomycetemcomitans, C. hominis, Eikenella corrodens, and Kingella species), is a rare cause of endocarditis. There are 61 reported cases of C. hominis infective endocarditis in the English-language literature, 15 of which involved prosthetic valve endocarditis. There is one reported case of C. hominis after upper endoscopy and none reported after colonoscopy. Presented here are two cases of C. hominis prosthetic valve endocarditis following colonoscopy and a review of the microbiological and clinical features of C. hominis endocarditis. Patients with C. hominis infection have a long duration of symptoms preceding diagnosis (138+/-128 days). The most common symptoms were fever (74%), fatigue/malaise (53%), weight loss/anorexia (40%), night sweats (24%), and arthralgia/myalgia (21%). The most common risk factors were pre-existing cardiac disease (61%), the presence of a prosthetic valve (28%), and history of rheumatic fever (20%). Of the 61 cases reviewed here, the aortic valve was infected in 24 (39%) and the mitral valve in 19 (31%) patients. The average duration of blood culture incubation before growth was detected was 6.3 days (range, 2-21 days). Complications were congestive heart failure (40%), central nervous system (CNS) emboli (21%), arrhythmia (16%), and mycotic aneurysm (9%). C. hominis is almost always susceptible to beta-lactam antibiotics. Ceftriaxone is recommended by the recently published American Heart Association guidelines. The prognosis of C. hominis native valve and prosthetic valve endocarditis is favorable. The cure rate among 60 patients reviewed was 93% (56/60). For prosthetic valve endocarditis, the cure rate was 16/17 (94%). Valve replacement was required in 27 (45%) cases.

Cardiobacterium hominis endocarditis in a patient with a hypersensitivity reaction to penicillin. Successful treatment with partial resection of the posterior mitral valve leaflet and antibiotic therapy with cefazolin

A 43-year-old patient with preexisting mitral valve prolapse and Cardiobacterium hominis endocarditis with partial destruction of the posterior mitral valve leaflet is described. Successful treatment was achieved with partial resection of the posterior mitral valve leaflet and antibiotic therapy. Because of a hypersensitivity reaction, initial therapy with penicillin G and gentamicin was stopped and substituted with cefazolin. No relapse of endocarditis was observed after 12 months of follow-up. Using micro broth dilution technique the isolated strain was shown to be most susceptible to penicillin G, cephalothin, and ciprofloxacin, with minimal inhibitory concentrations of 0.00025, 0.004, and 0.002 mg/l, respectively; and with minimal bactericidal concentrations (99.9% killing) of 0.25, 0.12, and 0.008 mg/l, respectively. We conclude that cephalosporins of the first generation or ciprofloxacin may be good alternatives to penicillin G in the treatment of C. hominis infection in patients known to be hypersensitive to penicillin.