title: Nontuberculous Mycobacteria: An Underestimated Cause of Bioprosthetic Valve Infective Endocarditis.
abstract: Background.  Atypical mycobacteria, or nontuberculous mycobacteria (NTM), have been barely reported as infective endocarditis (IE) agents. Methods.  From January 2010 to December 2013, cardiac valve samples sent to our laboratory as cases of blood culture-negative suspected IE were analyzed by 16S rDNA polymerase chain reaction (PCR). When positive for NTM, hsp PCR allowed species identification. Demographic, clinical, echocardiographic, histopathological, and Ziehl-Neelsen staining data were then collected. Results.  Over the study period, 6 of 370 cardiac valves (belonging to 5 patients in 3 hospitals) were positive for Mycobacterium chelonae (n = 5) and Mycobacterium lentiflavum (n = 1) exclusively on bioprosthetic material. The 5 patients presented to the hospital for heart failure without fever 7.1-18.9 months (median 13.1 months) after biological prosthetic valve implantation. Echocardiography revealed paravalvular regurgitation due to prosthesis dehiscence in all patients. Histopathological examination of the explanted material revealed inflammatory infiltrates in all specimens, 3 of which were associated with giant cells. Gram staining and conventional cultures remained negative, whereas Ziehl-Neelsen staining showed acid-fast bacilli in all patients. Allergic etiology was ruled out by antiporcine immunoglobulin E dosages. These 5 cases occurred exclusively on porcine bioprosthetic material, revealing a statistically significant association between bioprosthetic valves and NTM IE (P < .001). Conclusions.  The body of evidence confirmed the diagnosis of prosthetic IE. The statistically significant association between bioprosthetic valves and NTM IE encourages systematic Ziehl-Neelsen staining of explanted bioprosthetic valves in case of early bioprosthesis dysfunction, even without an obvious sign of IE. In addition, we strongly question the cardiac bioprosthesis conditioning process after animal sacrifice.
authors.affiliation: Laboratoire de Bactériologie, Centre de Biologie Est , Hospices Civils de Lyon , Bron.
authors.forename: Coralie
authors.initials: C
authors.lastname: Bouchiat
authors.affiliation: Maladies Infectieuses , Hospices Civils de Lyon.
authors.forename: Julien
authors.initials: J
authors.lastname: Saison
authors.affiliation: Laboratoire de Bactériologie, Centre de Biologie Est , Hospices Civils de Lyon , Bron.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Boisset
authors.affiliation: Laboratoire de Biometrie et Biologie Evolutive , Université Lyon 1-CNRS UMR 5558 , Bâtiment Mendel, Villeurbanne.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Flandrois
authors.affiliation: Maladies Infectieuses , Clinique du Tonkin , Villeurbanne.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Issartel
authors.affiliation: Laboratoire de Bactériologie, Centre de Biologie Est , Hospices Civils de Lyon , Bron.
authors.forename: Olivier
authors.initials: O
authors.lastname: Dauwalder
authors.affiliation: Laboratoire de Bactériologie, Centre de Biologie Est , Hospices Civils de Lyon , Bron.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Benito
authors.affiliation: Laboratoire de Bactériologie, Centre de Biologie Est , Hospices Civils de Lyon , Bron.
authors.forename: Sophie
authors.initials: S
authors.lastname: Jarraud
authors.affiliation: Unité d'Hygiène et d'Épidémiologie, Hospices Civils de Lyon , Bron.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Grando
authors.affiliation: Maladies Infectieuses , Hospices Civils de Lyon.
authors.forename: Andre
authors.initials: A
authors.lastname: Boibieux
authors.affiliation: Laboratoire de Bactériologie, Centre Hospitalier Lyon Sud , Hospices Civils de Lyon , Pierre-Bénite.
authors.forename: Oana
authors.initials: O
authors.lastname: Dumitrescu
authors.affiliation: Service de Cardiologie, Hôpital Louis Pradel, Hospices Civils de Lyon, Bron.
authors.forename: François
authors.initials: F
authors.lastname: Delahaye
authors.affiliation: Service de Chirurgie Cardiaque, Hôpital Louis Pradel, Hospices Civils de Lyon, Bron.
authors.forename: Fadi
authors.initials: F
authors.lastname: Farhat
authors.affiliation: Service d'Anatomo-Pathologie, Centre de Biologie Est , Hôpital Louis Pradel, Hospices Civils de Lyon , Bron.
authors.forename: Françoise
authors.initials: F
authors.lastname: Thivolet-Bejui
authors.affiliation: Service de Chirurgie Cardiaque , Clinique du Tonkin , Villeurbanne ; Service de Chirurgie Cardiaque , Infirmerie Protestante , Caluire-et-Cuire , France.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Frieh
authors.affiliation: Laboratoire de Bactériologie, Centre de Biologie Est , Hospices Civils de Lyon , Bron.
authors.forename: François
authors.initials: F
authors.lastname: Vandenesch
keywords: bioprosthetic valve; infective endocarditis; nontuberculous mycobacteria