Mycobacterial Prosthetic Valve Endocarditis

Abstract

Prosthetic valve endocarditis (PVE) due to mycobacteria is a rare but frequently fatal complication that may occur early after the surgical procedure, or even years later. Infection has been described with both mechanical and biologic valvular prosthesis. The most commonly implicated mycobacterial species belong to the rapid-grower group (M. chelonei, M. fortuitum, and M. abscessus) of nontuberculous mycobacteria (NTM). The source of infection in this context is thought to be nosocomial, likely related to preoperative or intraoperative contamination of the prosthesis by contact with aqueous solutions containing the organisms. These infections are difficult to diagnose because blood cultures are often negative. Clinically, it is important to recognize the possibility of NTM-PVE in the differential diagnosis of culture-negative patients who develop signs and symptoms of endocarditis, whether they present early or late in onset after the surgical procedure. These patients should be treated with surgical removal of the infected valve, followed by adequate antimicrobial therapy based on the susceptibility of the species isolated from the valve or perivalvular tissue culture. In a significant number of patients, however, an unstable hemodynamic condition ensues, precluding surgical intervention, and therefore leading to a high mortality rate.

Prosthetic Valve Endocarditis and Bloodstream Infection Due to Mycobacterium chimaera

“…PVE due to mycobacteria most often involves environmental rapidly growing NTM, suggestive of a nosocomial waterborne source of infection. In the setting of a prosthetic valve and an infection due to waterborne pathogens, like NTM, contaminated cardioplegic and/or valve-preserving solutions and the water supply system of the operating room should be evaluated as a possible sources of infection (1). Alternatively, contamination of the sternotomy wound or colonization of the prosthetic material due to intravenous catheter-related bacteremia with NTM might be considered (10).…”

“…The reported cases in the literature are associated with the insertion of biological and also of mechanical valves (1). Cases of prosthetic valve endocarditis (PVE) due to NTM often involve rapidly growing mycobacteria.…”

Mycobacterium neoaurum Causing Prosthetic Valve Endocarditis

“…NTM PVE has been described in both mechanical and biologic valvular prostheses. Although the origin of NTM infection of prosthetic valves is unclear, the most recent reports suggest a nosocomial source [9]. A recently proposed mechanism is the contamination of the prosthetic valve before or during the surgical procedure [3].…”

Spontaneous endocarditis caused by rapidly growing non-tuberculous Mycobacterium chelonae in an immunocompetent patient with rheumatic heart disease

“…2 Endocarditis caused by these organisms is rare and usually involves prosthetic valve infections with M. chelonae. 3 We are reporting a case of spontaneous endocarditis caused by rapid grower M. chelonae. Even after giving appropriate treatment according to the culture & sensitivity report, she succumbed to her illness due to embolic stroke.…”