TABLE 1.
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 |
FA, Freund's adjuvant; AHG, aluminum hydroxide gel; N, no adjuvant.
Antibody 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.
Vaccinated BALB/c mice were challenged with S. aureus ATCC 2593 (5 × 107 CFU) by intravenous injection, and survival was monitored.
A log rank (Mantel-Cox) test was used to compare the PBS mock treatment (no adjuvant) and treatment groups.