TABLE 3.
Differentiating features of B. anthracis and similar Bacillus species
| Bacillus speciesa | Resultb
|
||
|---|---|---|---|
| Beta-hemolysis | Motility | Capsulec | |
| B. anthracis | − | − | + |
| B. cereus var. mycoides | − | V | − |
| B. cereus | + | + | − |
| B. thuringiensis | + | + | − |
| B. megaterium | − | V | − |
a
B. anthracis, B. cereus var.mycoides, B. cereus, and B. thuringiensis are members of the B. cereus group (Bacillus morphology group 1). Species in this group have similar colonial morphology and produce ellipsoidal spores that do not swell the sporangium.
b
+, positive; −, negative; V, variable. Data are based on information in reference 33.
c
Capsules are usually only seen in smears of infected material, not in smears made from growth on most commonly used laboratory media.