Article Text

Download PDFPDF
Misidentification of Brucella melitensis as Ochrobactrum species: potential pitfalls in the diagnosis of brucellosis
  1. Fergal Howley1,
  2. Sultan Abukhodair1,
  3. Eoghan de Barra1,
  4. Karina O'Connell2 and
  5. Cora McNally1
  1. 1 Infectious Diseases, Beaumont Hospital, Dublin, Ireland
  2. 2 Department of Clinical Microbiology, Beaumont Hospital, Dublin, Ireland
  1. Correspondence to Dr Fergal Howley; howleyfe{at}


We describe a case of brucellosis in a man in his 20s, who presented to the emergency department with a 1-month history of fevers, dry cough and knee pain. Blood cultures were positive after 55 hours and Ochrobactrum daejeonense was identified on matrix-assisted laser desorption/ionisation time of flight (MALDI-TOF) mass spectrometry. Ochrobactrum spp are Gram-negative organisms that are phylogenetically related to Brucella spp but commercially available MALDI-TOF libraries cannot distinguish between the two genera. Further positive blood cultures for O. daejeonense combined with characteristic growth patterns for Brucella spp led to targeted questioning of the patient regarding potential exposure risks, which revealed a history of consumption of unpasteurised camel milk in the Middle East 3 months earlier. Treatment of brucellosis was initiated and subsequent whole genome sequencing identified the blood culture isolate as Brucella melitensis confirming the diagnosis of brucellosis. This case highlights the challenges in the diagnosis of brucellosis in low-incidence settings.

  • Infectious diseases
  • Tropical medicine (infectious disease)
  • Travel medicine

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Contributors The following authors were responsible for drafting of the text, sourcing and editing of clinical images, investigation results, drawing original diagrams and algorithms, and critical revision for important intellectual content: FH, SA, EdB, KO'C and CM. The following authors gave final approval of the manuscript: FH, SA, EdB, KO'C and CM.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.