title: Corynebacterium diphtheriae endocarditis: a case series and review of the treatment approach.
abstract: OBJECTIVE
  Infective endocarditis due to non-toxigenic Corynebacterium diphtheriae is uncommon; we report 10 cases occurring over a 14-year period in Auckland, New Zealand and review the approach for treatment.
  
  
  METHODS
  Eight of the 10 patients had known prosthetic valves or homografts in situ. Three patients required surgical intervention for infective endocarditis. Seven patients were treated with a combination of β-lactam and aminoglycoside, and one each was treated with a combination of vancomycin and an aminoglycoside, a β-lactam alone, and vancomycin alone. All patients survived and none relapsed.
  
  
  METHODS
  The antibiotic treatment of 46 previously reported cases was reviewed; patients treated with a β-lactam and aminoglycoside (n=25), and without the addition of an aminoglycoside (n=11) were compared. The differences in length of treatment within each group make the comparison of outcome (mortality, need for surgical intervention, disease and treatment complications) difficult. However, regardless of the length of treatment, there was no difference in mortality or need for surgical intervention between the two groups in the currently published cases.
  
  
  CONCLUSIONS
  Current evidence suggests that endocarditis of either native or prosthetic valves, caused by penicillin-susceptible C. diphtheriae, demonstrates a favorable outcome when treated with either a β-lactam alone or in combination with an aminoglycoside. Patient-specific factors will determine which approach is more appropriate for each individual patient.
authors.affiliation: Department of Microbiology, Auckland City Hospital, Private Bag 92026, Grafton, Auckland, New Zealand. sharmini.muttaiyah@uqconnect.edu.au
authors.forename: S
authors.initials: S
authors.lastname: Muttaiyah
authors.forename: E J
authors.initials: EJ
authors.lastname: Best
authors.forename: J T
authors.initials: JT
authors.lastname: Freeman
authors.forename: S L
authors.initials: SL
authors.lastname: Taylor
authors.forename: A J
authors.initials: AJ
authors.lastname: Morris
authors.forename: S A
authors.initials: SA
authors.lastname: Roberts
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003353:Corynebacterium diphtheriae; D004165:Diphtheria / Q000188:drug therapy / Q000382:microbiology / Q000628:therapy*; D004697:Endocarditis, Bacterial / Q000188:drug therapy / Q000382:microbiology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents