Table 2.

Rates of TFPI inactivation versus plasminogen and FVII activation by omptin-positive bacteria

Strain	TFPI inactivation rate (molecules/minute per cfu)	Plasminogen activation rate (molecules/minute per cfu)	FVII activation rate (molecules/minute per cfu)
Y pestis KIM5	217 000 + 42 000	900 + 17	1980 + 540
S Typhimurium ΔgalETK	2100 + 170	ND	ND
E coli MC4100	204 000 + 30 000	ND	ND

Tissue pathway factor inhibitor (TFPI) inactivation rates were determined by incubating TFPI and bacteria for various times at 37°C, then quantifying TFPI activity in clotting assays. Remaining TFPI activities were determined by reference to standard curves using purified TFPI. Experimental conditions resulting in insufficient plasmin or FVIIa for accurate determination of activation rates are listed as not detectable (ND). The lower limit of detection for both assays corresponded to an activation rate of approximately 50 molecules/minute per cfu. Results are mean plus SEM (n = 3).