Difficile examen direct par coloration de Gram : à propos d’un cas d’endocardite à Cardiobacterium hominis et revue de la littérature

Abstract

Cardiobacterium hominis is a Gram negative rod causing infectious endocarditis (IE), mainly in patients with congenital heart disease or prosthetic valves. The identification of this bacterium is often difficult and could be responsible for a delay in the diagnosis and the treatment that could be a source of cardiac complications. We report here a case of sepsis with infectious endocarditis due to Cardiobacterium hominis, its identification and treatment as well as a review of the literature.

Cardiobacterium hominis infective endocarditis: A literature review

“…Currently, there are two species of Cardiobacterium : C. hominis and Cardiobacterium valvarum . In these HACEK IE cases, C. hominis and C. valvarum account for 13 % and 1 %, respectively [5] , [6] . It is difficult to differentiate between C. hominis and C. valvarum .…”

“…Although C. hominis has relatively low virulence, IE complicates 88–95 % of all bacteremia cases [5] , [40] , [48] . It is difficult to biologically identify C. hominis because of its significantly slow growth and requirement of special enriched media for growth [6] , [7] . Bacterial culture is usually performed in standard enriched media, and optimal growth is achieved in the presence of 5 % CO 2 .…”

“…The culture is weak in a microaerophilic atmosphere and negative in an anaerobic atmosphere. Therefore, in some cases, the identification of C. hominis requires a significant period of time [2] , [6] , [13] . Our review revealed that there was a case in which the culture extended until 6 weeks to identify the organism [24] .…”

“…In these HACEK IE cases, C. hominis accounts for 13 % of cases; therefore, C. hominis IE is significantly rare, with an incidence rate of approximately 0.17–0.18 % [5] . It is difficult to biologically identify C. hominis because of its variability in Gram coloration and slow growth in the culture media [6] , [7] . Owing to its rare nature, the clinical features and prognosis of C. hominis IE remain unclear.…”

“…We searched the PubMed database to identify case reports of C. hominis IE and found 44 cases reported between January 2000 and June 2022 [1] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] . Herein, previously reported cases of C. hominis IE were reviewed and summarized.…”