TABLE 1.
Direct microbicidal action of hydrogen peroxide in the absence and presence of human erythrocytes
| Microbe | H2O2 concn (mM) | No. of CFU/mla |
Hemoglobin contenta,b |
||
|---|---|---|---|---|---|
| Without RBCs | With RBCs (107) | Supernatant | Pellet | ||
| E. coli | 0.0000 | 1,600,000 | 1,300,000 | 0.0 | 0.9 |
| 700.0000 | 0 | 10,000 | 0.0 | 0.0 | |
| 70.0000 | 0 | 1,100,000 | 0.0 | 0.4 | |
| 7.0000 | 670,000 | 1,300,000 | 0.1 | 0.9 | |
| 0.7000 | 1,600,000 | 1,200,000 | 0.1 | 0.9 | |
| 0.0700 | 1,300,000 | 1,700,000 | 0.1 | 0.9 | |
| 0.0070 | 1,600,000 | 1,200,000 | 0.1 | 0.9 | |
| 0.0007 | 1,200,000 | 1,300,000 | 0.0 | 1.0 | |
| S. aureus | 0.0000 | 1,200,000 | 1,300,000 | 0.0 | 0.9 |
| 700.0000 | 0 | 280,000 | 0.0 | 0.0 | |
| 70.0000 | 0 | 1,600,000 | 0.0 | 0.4 | |
| 7.0000 | 0 | 1,600,000 | 0.1 | 0.9 | |
| 0.7000 | 880,000 | 1,500,000 | 0.1 | 0.9 | |
| 0.0700 | 1,400,000 | 1,400,000 | 0.1 | 0.9 | |
| 0.0070 | 1,400,000 | 1,200,000 | 0.1 | 0.9 | |
| 0.0007 | 1,400,000 | 1,200,000 | 0.0 | 1.0 | |
| P. aeruginosa | 0.0000 | 2,000,000 | 2,000,000 | 0.0 | 0.9 |
| 700.0000 | 0 | 0 | 0.0 | 0.0 | |
| 70.0000 | 0 | 2,200,000 | 0.1 | 0.2 | |
| 7.0000 | 4,500 | 1,700,000 | 0.1 | 0.9 | |
| 0.7000 | 2,000,000 | 1,800,000 | 0.1 | 0.9 | |
| 0.0700 | 1,600,000 | 1,700,000 | 0.1 | 0.9 | |
| 0.0070 | 1,200,000 | 2,000,000 | 0.1 | 0.9 | |
| 0.0007 | 1,400,000 | 1,700,000 | 0.1 | 0.9 | |
| C. albicans | 0.0000 | 190,000 | 350,000 | 0.0 | 1.0 |
| 700.0000 | 78,000 | 150,000 | 0.0 | 0.0 | |
| 70.0000 | 230,000 | 300,000 | 0.0 | 1.0 | |
| 7.0000 | 150,000 | 380,000 | 0.0 | 1.0 | |
| 0.7000 | 180,000 | 330,000 | 0.0 | 1.0 | |
| 0.0700 | 170,000 | 280,000 | 0.0 | 0.9 | |
| 0.0070 | 160,000 | 290,000 | 0.0 | 0.9 | |
| 0.0007 | 270,000 | 320,000 | 0.0 | 1.0 | |
a
Values in boldface are less than 3 SDs from the expected mean and therefore indicate significant killing or significant hemolysis.
b
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. The yield of 107 RBCs is 0.25 to 0.34 mg of Hgb. The total Hgb distributed in the pellet and supernatant is expressed as proportions of unity (i.e., 1.0).