title: Culture-negative prosthetic valve endocarditis with concomitant septicemia due to a nontoxigenic Corynebacterium diphtheriae biotype gravis isolate in a patient with multiple risk factors.
abstract: A 54-year-old female with a prosthetic mitral valve presented with a 3-day history of dizziness, subjective fever, and chills. Blood cultures were positive for a pleomorphic Gram-positive rod. Initial phenotypic testing could only support the identification of a Corynebacterium species. Nucleic acid sequencing (16S rRNA) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) were conclusive for Corynebacterium diphtheriae. Definitive phenotypic testing classified the strain as nontoxigenic C. diphtheriae biotype Gravis.
authors.affiliation: Diagnostic Laboratory Services, Inc. (The Queen's Medical Center), Aiea, Hawaii, USA.
authors.forename: Lani Kai
authors.initials: LK
authors.lastname: Clinton
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Bankowski
authors.forename: Teppei
authors.initials: T
authors.lastname: Shimasaki
authors.forename: Wichit
authors.initials: W
authors.lastname: Sae-Ow
authors.forename: A Christian
authors.initials: AC
authors.lastname: Whelen
authors.forename: Norman
authors.initials: N
authors.lastname: O'Connor
authors.forename: Wesley
authors.initials: W
authors.lastname: Kim
authors.forename: Royden
authors.initials: R
authors.lastname: Young
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003354:Corynebacterium Infections / Q000175:diagnosis* / Q000382:microbiology*; D003353:Corynebacterium diphtheriae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004167:Diphtheria Toxin / Q000235:genetics; D004697:Endocarditis, Bacterial / Q000150:complications* / Q000175:diagnosis* / Q000382:microbiology; D005260:Female; D006801:Humans; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D016459:Prosthesis-Related Infections / Q000175:diagnosis / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012307:Risk Factors; D018805:Sepsis / Q000150:complications* / Q000175:diagnosis* / Q000382:microbiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D004167:Diphtheria Toxin; D012336:RNA, Ribosomal, 16S