TABLE 1.

Immunization with different doses and forms of rSaEsxA and rSaEsxB against S. aureus infection

Treatment	Dose (μg)	Adjuvanta	Titer ofb:						% survivalc	Significanced
			Anti-rSaEsxA IgG	Anti-rSaEsxA IgG1	Anti-rSaEsxA IgG2a	Anti-rSaEsxB IgG	Anti-rSaEsxB IgG1	Anti-rSaEsxB IgG2a
rSaEsxA	50	N	2.0 × 104 ± 5.0 × 103	1.5 × 104 ± 3.9 × 103	8.0 × 103 ± 1.8 × 103	<20	ND	ND	66.70	P < 0.05
	50	AHG	8.5 × 104 ± 1.1 × 104	5.9 × 104 ± 1.2 × 104	9.7 × 104 ± 2.5 × 103	<20	ND	ND	88.90	P < 0.0001
	50	FA	9.6 × 104 ± 1.1 × 104	6.4 × 104 ± 1.1 × 104	1.1 × 104 ± 2.3 × 103	<20	ND	ND	83.30	P < 0.0001
	10	FA	7.2 × 104 ± 2.5 × 104	ND	ND	<20	ND	ND	75.00	P < 0.005
	3	FA	5.4 × 104 ± 3.0 × 104	ND	ND	<20	ND	ND	75.00	P < 0.005
rSaEsxB	50	N	<50	ND	ND	1.2 × 105 ± 3.1 × 104	9.6 × 105 ± 1.4 × 105	4.3 × 105 ± 6.7 × 104	50.00	P < 0.05
	50	AHG	<50	ND	ND	1.2 × 106 ± 1.8 × 105	1.1 × 106 ± 1.7 × 105	3.3 × 105 ± 4.6 × 104	77.78	P < 0.0001
	50	FA	<50	ND	ND	2.6 × 106 ± 1.9 × 105	1.8 × 106 ± 1.4 × 105	3.8 × 105 ± 4.4 × 104	83.30	P < 0.0001
	10	FA	<10	ND	ND	2.6 × 106 ± 8.0 × 104	ND	ND	62.50	P < 0.005
	3	FA	<10	ND	ND	1.9 × 105 ± 6.4 × 104	ND	ND	50.00	P < 0.05
rSaEsxA+B	50	AHG	8.0 × 104 ± 1.1 × 104	6.9 × 104 ± 1.0 × 104	1.2 × 104 ± 2.1 × 103	1.3 × 106 ±1.9 × 105	1.0 × 106 ± 1.7 × 105	6.0 × 104 ± 1.2 × 104	83.30	P < 0.0001
PBS (mock)	0	FA	<10	<10	<10	<10	<10	<10	22.20	P = 0.7861
	0	AHG	<10	<10	<10	<10	<10	<10	16.70	P = 0.7250
	0	N	<10	<10	<10	<10	<10	<10	11.10

^aFA, Freund's adjuvant; AHG, aluminum hydroxide gel; N, no adjuvant.

^bAntibody titers (titers ± SEM) were detected by ELISA with purified rSaEsxA or rSaEsxB (1 μg/ml); the antibody endpoint titer was defined as the serum dilution that produced an OD₄₅₀ of 0.5 absorbance unit in the ELISA. ND, not determined.

^cVaccinated BALB/c mice were challenged with S. aureus ATCC 2593 (5 × 10⁷ CFU) by intravenous injection, and survival was monitored.

^dA log rank (Mantel-Cox) test was used to compare the PBS mock treatment (no adjuvant) and treatment groups.