TABLE 1.

The GBS Δstp1 mutant is attenuated for virulence

Moribund 50 (MD₅₀) estimates and confidence intervals were calculated as described under “Experimental Procedures.” The p value compares the value of the mutant strain with the WT A909 (p values of <0.05 were considered significant). NA, not applicable.

Strain	MD50	95% confidence interval	p value
	cfu
A909 (WT)	3.9 × 105	1.8 × 105 to 8.3 × 105	NA
Δstp1	5.3 × 108	9.5 × 107 to 3 × 1010	<0.001