title: Prosthetic valve endocarditis caused by Bordetella holmesii, an Acinetobacter lookalike.
abstract: We report a case of fulminant endocarditis on a prosthetic homograft aortic valve caused by Bordetella holmesii, which was successfully managed by surgical valve replacement and antibiotic treatment. B. holmesii, a strictly aerobic, small, Gram-negative coccobacillus, has been implicated as an infrequent cause of a pertussis-like syndrome and other respiratory illnesses. However, B. holmesii is also a rare cause of septicaemia and infective endocarditis, mostly in immunocompromised patients. To our knowledge, this is the first report of B. holmesii endocarditis on a prosthetic aortic valve. Routine laboratory testing initially misidentified the strain as Acinetobacter sp. Correct identification was achieved by 16S rRNA gene and outer-membrane protein A (ompA) gene sequencing. Interestingly, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry also produced an accurate species-level identification. Subsequent susceptibility testing and review of the literature revealed ceftazidime, cefepime, carbapenems, aminoglycosides, fluoroquinolones, piperacillin/tazobactam, tigecycline and colistin as possible candidates to treat infections caused by B. holmesii.
authors.affiliation: Department of Clinical Microbiology, Heilig-Hartziekenhuis Roeselare-Menen, 8800 Roeselare, Belgium.
authors.forename: Stijn
authors.initials: S
authors.lastname: Jonckheere
authors.affiliation: Department of Molecular Diagnostics, Heilig-Hartziekenhuis Roeselare-Menen, 8800 Roeselare, Belgium.
authors.forename: Thierry
authors.initials: T
authors.lastname: De Baere
authors.affiliation: Department of Cardiac Surgery, Heilig-Hartziekenhuis Roeselare-Menen, 8800 Roeselare, Belgium.
authors.forename: Pascal
authors.initials: P
authors.lastname: Schroeyers
authors.affiliation: National Reference Centre for Bordetella pertussis, Department of Microbiology and Infection Control, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels, Belgium.
authors.forename: Oriane
authors.initials: O
authors.lastname: Soetens
authors.affiliation: National Reference Centre for Bordetella pertussis, Department of Microbiology and Infection Control, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels, Belgium.
authors.forename: Annelies
authors.initials: A
authors.lastname: De Bel
authors.affiliation: Department of Clinical Microbiology, Heilig-Hartziekenhuis Roeselare-Menen, 8800 Roeselare, Belgium.
authors.forename: Ignace
authors.initials: I
authors.lastname: Surmont
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001884:Bordetella / Q000145:classification / Q000302:isolation & purification*; D001885:Bordetella Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology / Q000601:surgery; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004697:Endocarditis, Bacterial / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology / Q000601:surgery; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology / Q000601:surgery; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S