TABLE 2.

Effect of intravenous injection of fusobacteria on pregnancy outcome in mice

F. nucleatum strain	Dose (CFU)	No. of mice infected	No. of pups delivereda	No. of dead pupsa,b	Death ratec (%)	LD50 (CFU)d
12230	4 × 105	3	49	3	6	4 × 107
	2 × 107	8	87	20	23
	4 × 107	12	126	77	61
	7 × 107	6	63	59	93
12230 lam	4 × 106	3	30	0	0	6 × 107
	2 × 107	5	33	3	9
	4 × 107	4	35	7	20
	1 × 108	4	36	36	100
2929	8 × 106	8	91	18	20	2 × 107
	1 × 107	4	47	32	68
	3 × 107	4	44	27	61

^aValues shown were combined for all mice infected with the same dose.

^bIncludes premature births and term stillbirths.

^cThe death rate was calculated as (number of dead pups)/(number of pups delivered) × 100. The dead pup values include all pups delivered dead, either at term or prematurely, and those that died after delivery.

^dThe LD₅₀ was determined as the dose that resulted in a fetal death rate of 50% and was calculated as described in Materials and Methods.