Misidentification of Brucella melitensis as Bergeyella zoohelcum by MicroScan WalkAway®: a case report.

Objective: To describe the misidentification of Brucella melitensis as Bergeyella zoohelcum by MicroScan WalkAway®, a commonly used bacterial identification system.

Clinical Presentation And Intervention: A 35-year-old man was admitted to the Intensive Care Unit with sepsis syndrome. Three sets of aerobic blood culture samples were positive after 48 h of incubation. The isolated organism was identified as B. zoohelcum using the MicroScan WalkAway (Siemens Healthcare Diagnostics Inc., West Sacramento, Calif., USA). However, due to the rareness of the pathogen, the isolate was reidentified as B. melitensis with Vitek® 2 system and later 16S ribosomal sequence analysis confirmed the isolate as B. melitensis having 100% match.

Conclusion: This case showed that Brucella can be misidentified using MicroScan WalkAway. Countries where brucellosis is endemic need to be careful while using such automated identification systems in order not to miss the diagnosis of Brucella.