Prosthetic Valve Endocarditis and Bloodstream Infection Due to Mycobacterium chimaera

Abstract

dProsthetic valve endocarditis (PVE) due to fast-growing nontuberculous mycobacteria (NTM) has been reported anecdotally. Reports of PVE with slowly growing NTM, however, are lacking. We present here one case of PVE and one case of bloodstream infection caused by Mycobacterium chimaera. Randomly amplified polymorphic DNA (RAPD)-PCR indicated a relatedness of the two M. chimaera strains. Both patients had heart surgery 2 years apart from each other. A nosocomial link was not detected. Infective endocarditis due to nontuberculous mycobacteria (NTM) is a rare complication after heart valve surgery. 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. To date, there have been no concise reports on slowly growing mycobacteria, such as the Mycobacterium avium complex (MAC), as the agent causing PVE. However, the MAC is found occasionally on resected heart valves. A case series examining microbiological cultures from valves found slowly growing NTM in 5.5% of the cases without further clinical or histopathological evidence of infective endocarditis (IE) (2).MAC members are the most common cause of NTM infections in humans. M. intracellulare and M. avium are the main representatives of the MAC, but different MAC sequevars, e.g., M. chimaera, have been identified in recent years (3). Similar to other members of the MAC, M. chimaera has been reported to cause mainly pulmonary disease (3). In the summer of 2011, we encountered one fatal case of definite PVE and one fatal bloodstream infection due to M. chimaera. Randomly amplified polymorphic DNA (RAPD)-PCR was used to study the relatedness of the M. chimaera isolates from these two patients.(Part of this research was presented at the 101st Annual Meeting of the United States and Canadian Academy of Pathology, Vancouver, BC, Canada, 17 to 23 March 2012.) CASE REPORTS Patient 1. In June 2011, a 58-year-old male was admitted to the hospital for mitral and aortic valve replacement. In 2008, the patient had undergone aortic and mitral reconstruction with implantation of a mitral annuloplasty ring. Twelve months prior to the current admission, the patient experienced intermittent fever, weight loss, and respiratory distress. PVE was ruled out with repeated negative conventional blood cultures and a transesophageal echocardiogram that showed only moderate mitral and aortic insufficiency not suggestive of infective endocarditis. At that time, systemic sarcoidosis had been diagnosed based on unspecific granulomatous inflammation in liver and kidney biopsy specimens, a reticular pattern on the chest X ray together with a severely constrained CO diffusion capacity, and a bronchoalveolar lavage showing a predominance of lymphocytes but only a slightly elevated CD4/CD8 quotient. A Mycobacterium genus PCR from the preserved liver and kidney biopsy specimens was performed retrospectively 1 year later and showed negative re...

Microbiological problems and biofilms associated with Mycobacterium chimaera in heater–cooler units used for cardiopulmonary bypass

“…The first report of M. chimaera infections following cardiac surgery was published in 2013 40 . A follow-up investigation by Sax et al, described a total of 6 M. chimaera prosthetic valve endocarditis or vascular graft infections and an epidemiological link to HCUs utilised during surgery 1 Interestingly, the potential significance of HCUs in infection control was determined as early as 2002 in a publication that highlighted HCU microbial contamination, malfunctions, possible patient exposure routes, incompatibility of biocides with HCU components and problems regarding effective decontamination 48 .…”

Mycobacterium chimaera Infections Associated With Contaminated Heater-Cooler Devices Among Open Cardiac Surgery Patients: A Global Outbreak

“…Yaşayan hastalar, debridman ve antibiyotiklerle tedavi olmuş lokalize infeksiyonu olanlar (örneğin sternal cerrahi alan infeksiyonu) ve disemine infeksiyonu olup tedavi altında halen iyi olmayanlardır. Çok az sayıdaki hastada ise antibiyotik tedavisiyle birlikte yabancı cisim çıkarılmış olup, hastalar şu anda ameliyat sonrası izleme dönemindedir (1,2,5,6,8,23,29). Sonuç olarak, atfedilen mortaliteyi ve yabancı cismin çıkarıl-masının infeksiyonun iyileşmesine etkisini daha iyi tanımla-mak için daha fazla klinik deneyim ve daha uzun süreli hasta takibi yapılması gerekmektedir.…”

“…Ek olarak hastanelerin çoğu MAC'ı ancak kompleks düzeyinde tanımlayabilmektedir; tür düzeyinde tanımlama için, sadece referans laboratuvarların-da bulunan moleküler yöntemler gereklidir. Bir diğer olgu yakalama yolu sarkoidoz veya vaskülit tanısı almış hastaların, maruz kalma öyküsü olan hastaların listeleriyle karşılaştırıl-masıdır; çünkü hastalar sıklıkla, yanlışlıkla sarkoidoz olarak tanı konulabilen disemine granülomatöz süreçlerle başvur-maktadır (1,2,5,6,12,23,29).…”

Mycobacterium chimaera infections in post–operative patients exposed to heater–cooler devices: An overview

“…Signs and/or symptoms of invasive M. chimaera infection following exposure to aerosols from an HCD may not occur for months or years after exposure, with a mean time between exposure and diagnosis of 1.6 years (range: 0.1-6.3 years) (3,10,14,23,32). The infection usually presents as prosthetic valve endocarditis, vascular graft infection or disseminated infection although a variety of extracardiac sites may also be infected ( Table 1) (9)(10)(11)13,18,29,33).…”

“…Investigations of NTM infection clusters following cardiac surgery detected Mycobacterium chimaera as the causative microorganism. M. chimaera is a slow-growing NTM included in the Mycobacterium avium complex (3,(9)(10)(11)(12). It is less susceptible to disinfection procedures due to its cell wall constituents and its ability to form biofilms.…”