TABLE 1.
Genetic requirements for S. aureus Newman abscess formation in mice
| Genotype
|
Staphylococcal load in kidney tissue
|
Abscess formation in kidney tissue
|
||||
|---|---|---|---|---|---|---|
| Load (log10 CFU/g)a | Significance (P)b | Reduction (log10 CFU/g)c | Surface abscesses (%)d | Abscesses per kidneye | Significance (P)b | |
| Wild type | 6.141 ± 0.192 | — | — | 70 | 4.4 ± 0.9 | — |
| ΔsrtA
|
4.095 ± 0.347
|
6.7 × 10−6
|
2.046
|
0
|
0.0 ± 0.0
|
0.0216
|
| Surface protein genes
| ||||||
| sdrD | 4.092 ± 0.454 | 0.0001 | 2.049 | 15 | 0.6 ± 0.3 | 0.0265 |
| isdB | 4.535 ± 0.298 | 5.7 × 10−5 | 1.606 | 5 | 0.5 ± 0.2 | 0.0227 |
| clfB | 4.672 ± 0.302 | 0.0001 | 1.469 | 30 | 1.9 ± 0.7 | 0.1298 |
| isdA | 4.723 ± 0.299 | 0.0002 | 1.418 | 15 | 0.4 ± 0.2 | 0.0350 |
| isdC | 5.050 ± 0.208 | 0.0004 | 1.091 | 27 | 1.0 ± 0.3 | 0.0737 |
| clfA | 5.103 ± 0.260 | 0.0025 | 1.038 | 40 | 1.1 ± 0.4 | 0.0848 |
| spa | 5.137 ± 0.374 | 0.0144 | 1.004 | 13 | 0.4 ± 0.4 | 0.0356 |
| sasG | 5.139 ± 0.287 | 0.0054 | 1.002 | 45 | 1.2 ± 0.4 | 0.0770 |
| sasC | 5.193 ± 0.337 | 0.0167 | 0.948 | 56 | 1.4 ± 0.6 | 0.1335 |
| sasD | 5.312 ± 0.291 | 0.0212 | 0.829 | 48 | 1.5 ± 0.5 | 0.1272 |
| sasA | 5.355 ± 0.217 | 0.0102 | 0.786 | 39 | 2.3 ± 0.5 | 0.2568 |
| sdrE | 5.498 ± 0.255 | 0.0475 | 0.643 | 65 | 2.3 ± 0.7 | 0.5023 |
| sasF | 5.518 ± 0.318 | 0.0884 | 0.623 | 47 | 1.3 ± 0.4 | 0.3187 |
| isdH | 5.555 ± 0.251 | 0.0676 | 0.586 | 44 | 1.1 ± 0.5 | 0.0859 |
| sasB | 5.650 ± 0.255 | 0.1641 | 0.491 | 59 | 1.7 ± 0.6 | 0.1651 |
| fnbA | 5.678 ± 0.270 | 0.1294 | 0.463 | 51 | 2.1 ± 0.7 | 0.2338 |
| sdrC | 5.693 ± 0.287 | 0.1908 | 0.448 | 33 | 1.0 ± 0.4 | 0.0741 |
| fnbB | 5.823 ± 0.246 | 0.3124 | 0.318 | 54 | 2.0 ± 0.6 | 0.2074 |
| PNAG (PIA) genes | ||||||
| icaA | 5.326 ± 0.452 | 0.1122 | 0.815 | 40 | 2.7 ± 1.5 | 0.5768 |
| icaB | 5.894 ± 0.306 | 0.4917 | 0.247 | 35 | 1.0 ± 0.3 | 0.2690 |
| icaC | 5.651 ± 0.441 | 0.3004 | 0.491 | 35 | 2.0 ± 1.5 | 0.4384 |
| icaD | 5.886 ± 0.278 | 0.4394 | 0.255 | 45 | 1.7 ± 0.7 | 0.3741 |
| icaR | 6.201 ± 0.309 | 0.8837 | +0.06 | 60 | 2.3 ± 0.3 | 0.5018 |
| ica:tet | 5.692 ± 0.280 | 0.1909 | 0.449 | 55 | 2.3 ± 0.7 | 0.5023 |
| Envelope-associated protein genes | ||||||
| eap | 6.530 ± 0.385 | 0.1217 | +0.49 | 55 | 1.3 ± 0.4 | 0.0971 |
| emp | 5.540 ± 0.040 | 0.0576 | 0.601 | 20 | 0.8 ± 0.4 | 0.0361 |
| Capsular polysaccharide genes | ||||||
| capO | 6.028 ± 0.579 | 0.9825 | 0.113 | 50 | 3.0 ± 1.0 | 0.6035 |
a
Means ± se of staphylococcal load were calculated as log10 CFU/g in homogenized renal tissues 5 d following infection in cohorts of 15 BALB/c mice per challenge strain.
b
Statistical significance was calculated with the Students t test; values of P < 0.05 were deemed significant.
c
Reduction in bacterial load calculated as log10 CFU/g.
d
Abscess formation in kidney tissues 5 d following infection was measured by macroscopic inspection (% positive).
e
Histopathology of H&E-stained, thin-sectioned kidneys from 8–10 animals; average number of abscesses per kidney was recorded and averaged again for the final mean ± se.