Any isolate with the following features should be immediately referred to your LRN reference laboratory:
- Gram stain shows large, gram-positive rods with sub-terminal or central spores (if present)
- Gray colonies with a ground-glass appearance
- Non-hemolytic on sheep blood agar (SBA)
- Tenacious or "sticky" colonies like petroleum jelly
- Catalase positive
- Non-motile
