Clinical specimens where organism may be encountered:
- Blood
- Lymph node aspirate
- Respiratory secretions
Gram stain morphology:
- Gram-negative rod
- Resembles other Enterobacteriaceae
- Can form short chains
- Gram stains performed from blood culture or other liquid media may show bipolar staining (displayed by the arrows)
Note: Use of Wright-Giemsa staining on direct specimen may enhance demonstration of characteristic bipolar staining, also referred to as "safety-pin" morphology. Use of this staining is of limited value, as the method is not very sensitive or specific.
