TABLE 2.

Fine specificities, avidities, and bactericidal activities of MAbs^a

MAb	Specificity by FELISA	Specificity by PPTb			Concn at 50% bindingc			Concn at 50% killingd
		MCPS	OAc−	K92	MCPS	OAc−	K92	MCPS	OAc−
IgG3κ
2055.5	MCPS	+	−e	−	0.2	−f	−	0.18	−g
2016.3	OAc− >> MCPS	+	+	−	>3.0	0.1	−	0.63	1.1
IgG1κ
C2/1076.10	MCPS ≈ OAc− >>> K92	+	+	−h	0.005	0.002	1.5	NDi	ND
C2/655.7	OAc− >> MCPS	+	+	−	0.3	0.003	−	ND	ND
C2/256.8	MCPS ≈ OAc−	+	+	−	0.005	0.003	−	ND	ND

^aThe fine specificity and precipitation with MCPS and OAc⁻, the concentration at 50% binding of MAb, and 50% killing were published previously (23, 56).

^bDetermined by Ouchterlony precipitation (PPT) (48). Proteins were tested at 1 mg/ml. +, precipitation; −, no precipitation.

^cConcentration (micrograms per milliliter) at 50% binding were determined at the midpoint of the linear part of the titration curve on PS-coated plates. Proteins were tested by 12 threefold serial dilutions starting at 3 μg/ml.

^dThe concentration (micrograms per milliliter) of antibody at which 50% of the bacteria were killed.

^eNot detectable at highest concentration tested (1 mg/ml).

^fNot detectable at highest concentration tested (3 μg/ml).

^gNo detectable killing.

^hNegative using the purified protein, but undiluted ascites fluid was positive on all three Ags and negative on K1.

ⁱND, not determined.