Table 3.

Culture and immunological status of cattle used in this study.

			IFN-γ (mg/ml)c
Cow ID	Survey datea	Fecal culture (CFU)b	NS	ConA	MPS	ELISA (S/P ratio)d
85	12/20/05	C, C, C, C	0.069	0.454	0.278	0.002
	3/4/06	2, 2, 2	0.061	0.185	0.068	ND
112	12/20/05	C, C, 21, 1	0.07	0.218	0.064	0.027
	4/10/06	2, 1, 1	0.063	1.83	0.09	0.014
113	8/10/04	C, C, C, C	0.21	0.514	0.054	0.041
	11/10/04	0, 3, 1	0.39	1.51	0.54	0.09
117	12/17/04	T, T, T, T	0.053	0.143	0.097	-0.052
	3/1/05	T, C, C	0.039	0.174	0.046	ND
183	12/20/05	0, 0, C, C	0.054	0.241	0.145	1.42
	4/7/06	3, 2, 0	0.089	1.134	0.194	0.981
235	12/20/05	0, 0, 0, 0	0.068	0.362	0.114	0.039
	3/4/06	0, 1, 1	0.05	0.35	0.064	0.021
834	8/10/04	0, 1, 0, 1	0.033	0.336	0.142	0.87
	11/11/04	0, 0, 0	0.044	0.806	0.076	0.648
871	8/10/04	C, C, C, C	0.037	0.361	0.054	0.049
	12/21/04	C, 2, 1	0.043	0.189	0.064	0.121
2715	12/20/05	2, 0, 1, 0	0.067	1.3	0.324	0.226
	3/18/06	0, 0, 0	0.059	0.211	0.062	0.044

^aEach animal is surveyed quarterly to monitor progression of Johne's disease. The two most recent quarterly surveys are shown for each animal, but only sera collected on the most recent date was used for the immunoblot assay in Figure 4.

^bFecal culture is reported as numbers of colony forming units (CFU) present on each HYEM slant (platings are in triplicate or quadruplicate). A "C" indicates the slant had bacterial growth other than M. paratuberculosis. A "T" designation means too many colonies to count on that slant.

^cThe gamma interferon (IFN-γ) assay. Subclinical cows typically have a M. paratuberculosis sonicate (MPS) reading higher than the no stimulation (NS) reading, along with little or no colonies on fecal culture slants. The concanavalin A (ConA) reading is a positive control as cells are readily stimulated by this lectin protein.

^dThe ELISA sample to positive (S/P) ratio is calculated from the optical density reading as described previously [11].