TABLE 4.
Viridans group S. sanguinis-myeloperoxidase synergistic microbicidal action in the absence and presence of human erythrocytes
| Microbe added to S. sanguinis culturea | MPO concn (nM) | No. of CFU/mlb |
Hemoglobin contentc |
||
|---|---|---|---|---|---|
| Without RBCs | With RBCs (107) | Supernatant | Pellet | ||
| E. coli | 0.0 | 2,000,000 | 2,600,000 | 0.0 | 1.0 |
| 50.0 | 0 | 0 | 0.0 | 1.0 | |
| 16.7 | 0 | 0 | 0.0 | 1.0 | |
| 5.6 | 0 | 10,000 | 0.0 | 1.0 | |
| 1.9 | 10,000 | 930,000 | 0.0 | 1.1 | |
| 0.6 | 650,000 | 2,600,000 | 0.0 | 1.0 | |
| 0.2 | 1,900,000 | 2,500,000 | 0.0 | 1.0 | |
| S. aureus | 0.0 | 1,600,000 | 1,800,000 | 0.0 | 1.0 |
| 50.0 | 0 | 8,000 | 0.0 | 0.9 | |
| 16.7 | 0 | 740,000 | 0.0 | 1.0 | |
| 5.6 | 820,000 | 930,000 | 0.0 | 1.0 | |
| 1.9 | 430,000 | 1,900,000 | 0.0 | 1.0 | |
| 0.6 | 1,600,000 | 1,700,000 | 0.1 | 1.0 | |
| 0.2 | 1,700,000 | 1,900,000 | 0.0 | 1.0 | |
| P. aeruginosa | 0.0 | 2,000,000 | 3,400,000 | 0.0 | 1.0 |
| 50.0 | 0 | 0 | 0.1 | 1.0 | |
| 16.7 | 0 | 10,000 | 0.0 | 0.9 | |
| 5.6 | 0 | 7,200 | 0.0 | 0.9 | |
| 1.9 | 0 | 6,200 | 0.0 | 1.0 | |
| 0.6 | 0 | 520,000 | 0.1 | 1.0 | |
| 0.2 | 10,000 | 4,500,000 | 0.0 | 1.0 | |
| C. albicans | 0.0 | 200,000 | 240,000 | 0.0 | 1.0 |
| 50.0 | 0 | 4,000 | 0.0 | 0.8 | |
| 16.7 | 0 | 250,000 | 0.0 | 0.9 | |
| 5.6 | 0 | 180,000 | 0.0 | 1.0 | |
| 1.9 | 0 | 240,000 | 0.0 | 1.0 | |
| 0.6 | 6,000 | 250,000 | 0.0 | 1.0 | |
| 0.2 | 160,000 | 210,000 | 0.0 | 1.0 | |
a
Each suspension contained approximately 107 S. sanguinisbacteria plus the additional microbe, as indicated. Microbe concentration was estimated by the optical density measurement at 540 nm. No H2O2 was added.
b
Values in boldface are less than 3 SDs from the expected mean and therefore indicate significant killing.
c
RBC damage was assessed by measuring the hemoglobin (Hgb) retained in the pelleted intact RBCs, lost to the medium as a consequence of hemolysis, or completely destroyed by oxidation as described in footnote b of Table 1.