TABLE 3.

Effect of using single or combined complex and recombinant antigens on the diagnostic sensitivity of IgG1 ELISAs in M. paratuberculosis-infected deer^a

Infected animal	Mean EU value using:
	Complex antigens		Recombinant antigens
	PPDj	PpAg	3	4	7	10	15	16	17	20	21
1	210	145	0	0	0	23	67	76	71	65	63
2	86	102	0	0	0	0	75	84	81	64	0
3	54	43	4	0	0	0	27	26	39	37	0
4	70	79	4	6	17	6	0	0	0	0	11
5	120	135	14	57	0	11	0	0	0	0	0
6	173	56	2	0	2	24	0	0	0	0	14
7	7	20	30	0	46	17	0	0	2	59	0
8	32	64	0	0	0	4	3	0	12	0	0
9	0	94	0	0	0	0	112	90	10	103	0
10	8	15	11	0	49	2	5	13	24	13	19

^aIgG1 ELISAs were undertaken using sera from 10 known M. paratuberculosis-infected deer, with screening of reactivity against complex (PPDj, PpAg) or recombinant M. paratuberculosis antigens. Data represent mean EU values for each assay. Data in bold indicate cases predicted to be positive by the diagnostic assay (using cut points of 50 EU for complex antigen sources and 20 EU for recombinant antigens). Estimated sensitivity values were generally low for the recombinant antigens, except for antigen 7 (MAP2762c), which detected M. paratuberculosis-infected animals 7 and 10 that had been missed using the complex-antigen sources.