Evaluation of the Combined Use of Major Outer Membrane Proteins in the Serodiagnosis of Brucellosis

Figures & data

Table 1 Different Combinations of Outer Membrane Proteins

Combination No.	Protein Composition
Combination 1	omp10, omp16, omp19
Combination 2	omp31, BP26
Combination 3	omp25, omp31
Combination 4	omp25, omp31, BP26
Combination 5	omp10, omp16, omp19, omp25, omp31 and BP26

Figure 1 Indirect ELISA analysis of serum samples. (A) Dot plot of human sera. (B) ROC analysis of human sera.

Figure 2 Indirect ELISA analysis of serum samples. (A) Dot plot of goat sera. (B) ROC analysis of goat sera.

Table 2 Diagnostic Values of the Combinations Calculated for Different Cut-Off Values

Samples	Antigen	Cut-Off value	Positive		Negative		Accuracy (%)	PPV (%)	NPV (%)
			TP	FN	TN	FP
Human	Combination 1	>0.4271	98	13	49	1	91.30	98.99	79.03
	Combination 2	>0.5026	103	8	49	1	94.41	99.04	85.96
	Combination 3	>0.4739	100	11	50	0	93.17	100.0	81.97
	Combination 4*	>0.4756	105	6	50	0	96.27	100.0	89.29
	Combination 5	>0.4261	105	6	50	0	96.27	100.0	89.29
	LPS	>0.5066	100	11	50	0	93.17	100.0	81.97
Goat	Combination 1	>0.3569	55	11	38	16	77.50	77.46	77.55
	Combination 2*	>0.7855	47	19	54	0	84.17	100.0	73.97
	Combination 3	>0.7119	47	19	54	0	84.17	100.0	73.97
	Combination 4	>0.6280	52	14	51	3	85.83	94.55	78.46
	Combination 5	>0.6724	51	15	51	3	85.00	94.44	77.27
	LPS	>0.6198	51	15	52	2	85.00	96.23	77.61
Bovine	Combination 1	>0.3747	72	22	44	6	80.56	92.31	66.67
	Combination 2*	>0.6138	79	15	48	2	88.19	97.53	76.19
	Combination 3	>0.4700	85	9	45	5	90.28	94.44	83.33
	Combination 4	>0.6478	78	16	49	1	88.19	98.73	75.38
	Combination 5	>0.5398	81	13	47	3	88.89	96.43	78.33
	LPS	>0.5397	80	14	47	3	88.19	96.39	77.05

Note: *The best combination.

Figure 3 Indirect ELISA analysis of serum samples. (A) Dot plot of cattle sera. (B) ROC analysis of cattle sera.

Table 3 Specificity Results the Combinations in the Indirect ELISA Diagnostic Method

Antigen	Combination 1		Combination 2		Combination 3		Combination 4		Combination 5
	OD450	S/N	OD450	S/N	OD450	S/N	OD450	S/N	OD450	S/N
Yersinia enterocolitica O9	0.0667	0.59	0.0682	0.73	0.0629	0.67	0.0611	0.64	0.0701	0.59
E. coli O157:H7	0.0657	0.58	0.0665	0.71	0.0591	0.63	0.0585	0.61	0.0609	0.51
L.P.	0.1495	1.32	0.0935	1.00	0.0921	0.98	0.0994	1.04	0.153	1.29
Salmonella	0.4167	3.68*	0.0929	0.99	0.0984	1.05	0.1028	1.08	0.4157	3.51*
L.M.	0.0704	0.62	0.0729	0.78	0.0691	0.74	0.0691	0.73	0.0702	0.59
V.P.	0.5722	5.05*	0.1389	1.49	0.1328	1.42	0.1256	1.32	0.6017	5.08*
Vibrio cholerae	0.0782	0.69	0.102	1.09	0.1648	1.76	0.066	0.69	0.0683	0.58
Negative	0.1132	–	0.0934	–	0.0936	–	0.0953	–	0.1184	–

Notes: *S/N≥2.1, confirmed cross-reaction.