Detection of antibodies specific to the non-structural proteins of fowl adenoviruses in infected chickens but not in vaccinated chickens

Figures & data

Figure 1. SDS-PAGE and western blotting analysis of purified 100K-GST and 33K-GST fusion proteins. 1a: Coomassie brilliant blue staining of the purified 100K-GST and 33K-GST fusion proteins. Lane M, protein marker standards; lane 1, 100K-GST fusion protein; lane 2, 33K-GST fusion protein. 1b, 1c: Western blotting analysis of the 100K-GST and 33K-GST fusion proteins using known FadV-positive sera: (1b) Lane M, protein marker standards; lane 1, pGEX-4T-1 induced 5 h; lane 2, pGEX-4T-1 100K-GST fusion protein induced 5 h; and (1c) lane M, protein marker standard; lane 1, pGEX-4T-1 induced 5 h; lane 2, PGEX-4T-1 33K-GST fusion protein induced 5 h.

Table 1. Optimal concentrations of recombinant proteins and of serum dilutions used in ELISAs as determined by checkerboard titration assays.

		Serum dilution
		1:50		1:100		1:200		1:400
Type of ELISA	Concentration of protein (µg/ml)	+ serum^Footnotea	− serum^Footnoteb	+ serum	− serum	+ serum	− serum	+ serum	− serum
100K-ELISA	10.8	1.235^Footnotec	0.234	1.203	0.215	0.872	0.164	0.611	0.133
	5.4	1.019	0.173	0.904	0.140	0.726	0.131	0.529	0.110
	2.7	0.832	0.156	0.742	0.137	0.689	0.129	0.443	0.115
	1.4	0.591	0.137	0.451	0.120	0.374	0.110	0.244	0.098
33K-ELISA	12	0.977	0.195	0.903	0.182	0.753	0.159	0.536	0.132
	6	0.853	0.164	0.821	0.153	0.620	0.137	0.428	0.121
	4	0.760	0.159	0.712	0.148	0.584	0.123	0.391	0.115
	2	0.607	0.148	0.531	0.121	0.356	0.119	0.278	0.110
100K-33K-	10.8 (100K) + 12 (33K)	1.635	0.306	1.428	0.275	1.278	0.238	0.843	0.195
ELISA	5.4 (100K) + 6 (33K)	1.445	0.208	1.233	0.172	0.974	0.153	0.723	0.124
	2.7 (100K) + 4 (33K)	1.124	0.185	0.993	0.152	0.874	0.137	0.607	0.118
	1.4 (100K) + 2 (33K)	0.905	0.153	0.818	0.137	0.662	0.112	0.415	0.102
GST-ELISA^Footnoted	6 (GST)	0.275	0.089	0.153	0.066	0.088	0.052	0.067	0.040

^a FAdV-positive serum. ^bFAdV-negative serum. ^cThe values shown in the columns are the optical absorbances. ^dPurified GST protein was used as a coating antigen.

Table 2. Comparison of different methods for detecting FAdV-specific antibodies in field samples.

Origin of serum samples	Location of chicken farm	Number of samples	100K-ELISA-positive samples	33K-ELISA-positive samples	100K + 33K-ELISA positive samples	AGP-positive samples	Whole virus ELISA-positive samples
Chickens with suspected FAdV infection	Jvdong	50	21	20	21	18	23
	Jingxi	50	18	16	21	14	21
	Liangfeng	50	10	9	10	6	11
	Longan	50	22	20	24	15	26
	Total number of samples	200	71	65	76	53	81
	% positive		35.5	32.5	38	26.5	40.5
Chickens vaccinated with inactivated FAdV vaccine	Jvdong	43	0	0	0	31	40
	Jingxi	36	0	0	0	26	33
	Liangfeng	32	0	0	0	21	32
	Longan	39	0	0	0	24	37
	Total number of samples	150	0	0	0	102	142
	% positive		0	0	0	68	94.7