TABLE 3.

Binding of three MAbs recognizing different O-antigen epitopes to encapsulated K. pneumoniae parent strains and their decapsulated mutants

Strain	CPS serotype	ELISA ODa
		MAb			Control antibody (subclass)b			Anti-CPS-antibodyc	Control
		Ru-O1	IV/4-5	V/9-5	IgG2b	IgG3	IgG2a
Caroli	K2	0.049	0.010	0.030	0.000	0.001	0.000	3.159	0.124
Caroli/2	K−	2.452	1.575	1.433	0.000	0.000	0.000	0.063	0.014
591	K2	0.044	0.027	0.112	0.004	0.003	0.048	2.836	0.054
591/1	K−	3.511	3.560	3.362	0.003	0.022	0.058	0.328	0.000
37	K7	0.936	1.169	1.229	0.000	0.065	0.028	2.479	0.011
37/2a	K−	2.781	3.056	2.762	0.000	0.085	0.068	1.951	0.000
58	K7	1.419	0.909	1.177	0.009	0.049	0.017	1.185	0.003
58/5	K−	2.932	2.205	2.661	0.002	0.021	0.016	2.419	0.000
151	K21	2.214	0.653	0.611	0.000	0.000	0.004	3.197
151/1	K−	3.073	3.948	3.261	0.037	0.000	0.085	3.272
557	K21	0.452	0.423	0.635	0.017	0.012	0.032	1.580
557/2	K−	2.610	3.316	3.420	0.010	0.004	0.026	2.033

^aMean of four independent experiments, each done in duplicate. 

^bIrrelevant MAb of IgG2b subclass for MAb Ru-O1, IgG3 subclass for MAb IV/4-5, or IgG2a subclass for MAb V/9-5. 

^cAnti-K2 CPS antibody was MAb III/5-1, and the control was an irrelevant IgM MAb. Anti-K7 CPS and anti-K21 CPS antibodies were polyclonal rabbit and human IgG antibodies, respectively.