TABLE 4.
Virulence of A66 derivatives following i.n. inoculation of CBA/N micea
| Strain | Capsule phenotypeb | No. dead/no. total | No. colonized/no. alivec | Nasal washd log CFU/ml (± SEM) |
|---|---|---|---|---|
| A66 | Cps+ | 8/9 | 0/1 | — |
| AM188 | Cpsr | 3/10∗e | 3/7 | 3.16 (0.23) |
| AM199 | Cps− | 0/5∗∗e | 0/5 | — |
a
Mice were inoculated i.n. with 1 × 107 (A66), 3 × 107 (AM188), or 5 × 106 (AM199) CFU.
b
Cps+, parental levels of capsule; Cpsr, reduced capsule production; Cps−, nonencapsulated.
c
Values are the number of mice colonized/number of mice surviving the infection.
d
See footnote d in Table 2.
e
Significantly different from value for A66 (∗, P < 0.05; ∗∗, P = 0.003).