title: Mycobacterium fortuitum prosthetic valve endocarditis: a case for the pathogenetic role of biofilms.
abstract: BACKGROUND
  Prosthetic valve endocarditis presents unique challenges for both diagnosis and treatment. A potential role of biofilm has been hypothesized in the pathogenesis of these infections.
  
  
  METHODS
  A patient with infective endocarditis involving a stentless (Freestyle) porcine prosthetic aortic valve with annular abscess and paravalvular leak 8 months after implantation is reported.
  
  
  RESULTS
  The infected valve did not show vegetations or perforations, but histiocytic inflammation was seen along the endocardial surfaces of the valve. Auramine-rhodamine staining revealed many acid-fast organisms associated with the inflammation. There was also an acellular matrix material with ultrastructural features of biofilm. Blood cultures grew Mycobacterium fortuitum, a biofilm-associated microbe.
  
  
  CONCLUSIONS
  The role of biofilm in prosthetic valve endocarditis is discussed. The importance of microscopy for prosthetic valves, even when no vegetations are present, is highlighted along with correlation of pathologic findings with culture results.
authors.affiliation: Division of Anatomic Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Silvia
authors.initials: S
authors.lastname: Bosio
authors.forename: Surbhi
authors.initials: S
authors.lastname: Leekha
authors.forename: Scott I
authors.initials: SI
authors.lastname: Gamb
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Wright
authors.forename: Christine L
authors.initials: CL
authors.lastname: Terrell
authors.forename: Dylan V
authors.initials: DV
authors.lastname: Miller
mesh_terms: D000368:Aged; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D018441:Biofilms; D004359:Drug Therapy, Combination; D004696:Endocarditis / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology; D006350:Heart Valve Prosthesis / Q000382:microbiology*; D006801:Humans; D008297:Male; D009165:Mycobacterium Infections, Nontuberculous / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology; D019907:Mycobacterium fortuitum / Q000472:pathogenicity / Q000502:physiology*; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology; D012086:Reoperation; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents