Gemella morbillorumprosthetic aortic valve endocarditis

Abstract

SUMMARYGemella morbillorum is facultative anaerobic, Gram-positive cocci and are a commensal part of human flora. The reported patient in this case, with a prosthetic bovine aortic valve, presented with fever, poor dental hygiene, new cardiac murmur and signs of congestive heart failure. Blood cultures were positive for a viridans streptococcal species; however, the organism could not be further identified at our institution. Echocardiogram demonstrated a decrease in ejection fraction and vegetation attached to the prosthetic aortic valve associated with a perivalvular abscess. The patient was treated with a 6-week regimen of penicillin G with gentamicin for the first 2 weeks along with cardiac surgery. The results from the 16S rRNA gene sequencing of the viridans streptococcal species were available, which reported the organism as G. morbillorum. This case adds to the literature on G. morbillorum prosthetic valve endocarditis and provides additional evidence to consider infectious endocarditis in the setting of G. morbillorum bacteraemia. BACKGROUND

Risk Factors and Patient Profile of Infective Endocarditis due to <i>Gemella spp.</i>

“…All studies were published between 1989 and 2019. The majority of studies were conducted in Europe and the UK [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 30 , 32 , 34 , 35 , 36 , 37 , 38 , 40 , 46 , 47 , 49 , 52 , 56 , 57 , 58 , 60 , 61 , 66 , 68 , 72 , 73 , 75 , 84 , 92 ] followed by North America [ 15 , 17 , 19 , 21 , 29 , 31 , 33 , 39 , 43 , 45 , 48 , 54 , 55 , 64 , 67 , 69 , 71 , 76 , 77 , 78 , 79 , 83 , 86 , 88 , 89 , 90 ] and Asia. [ 14 , 16 , 18 , 20 , 41 , 44 , 50 , 51 , 53 , 62 , 63 , 65 , 74 ,…”

“…[ 14 , 52 , 65 , 77 , 86 ] 71.4% of studies did not include the post-intervention clinical condition of the patients and/or adverse or unanticipated events. [ 14 , 15 , 16 , 18 , 19 , 22 – 26 , 28 – 32 , 34 , 36 – 43 , 46 – 50 , 52 , 53 , 57 – 63 , 65 – 68 , 71 – 73 , 76 – 78 , 80 , 81 , 84 , 85 , 87 , 89 , 90 , 92 ]…”

“…The most common species was Gemella morbillorum (44.6%) [ 14 , 16 – 19 , 23 , 24 , 27 , 28 , 30 , 31 , 35 , 37 , 38 , 42 , 43 , 47 , 49 – 53 , 56 , 58 , 63 , 64 , 70 , 74 – 76 , 80 , 81 , 84 , 90 , 91 ] followed by Gemella haemolysans (26.5%). [ 15 , 21 , 22 , 25 , 26 , 32 , 36 , 40 , 46 , 48 , 52 , 54 , 59 – 61 , 68 , 69 , 72 , 73 , 88 , 92 ] The predominant strains in studies published in Europe and North America were Gemella morbillorum [ 17 , 19 , 23 , 24 , 27 , 28 , 30 , 31 , 35 , 37 , 38 , 43 , 47 , 49 , 52 , 56 , 57 , 64 , …”

Gemella morbillorumisolated from a pelvic abscess in an HIV-positive patient with squamous cell carcinoma of the perianal region

“…G. morbillorum is known to be a commensal organism of the human oropharyngeal, upper GI and genitourinary tract 1. It is rarely the cause of infection in humans, and when it is isolated, has mostly been so in the setting of infective endocarditis 3–5. To date, only two cases at a single centre have described skin and soft tissue infection with G. morbillorum ,8 making its presence here as the cause of a soft tissue infection concerning for an expanding role as a virulent pathogen in humans.…”

“…Originally classified as part of the Streptococcus genus, it was reclassified into the Gemella genus after further studied demonstrated significant similarity to G. hemolysans 2. In the literature, G. morbillorum has a well-documented role in infective endocarditis, particularly valvular disease 3–5. It has also been implicated in visceral abscess formation in multiple systems, including the liver and lungs 6 7.…”