TABLE 5.
Time course of bacterial recovery in mouse respiratory tract after an aerosol challenge with M. catarrhalis wild-type strain O35E and mutant O35EkdtA
| Groupa (sample source) | Bacterial recoveryb (CFU/mouse) (SD range) and reductionc (%) at:
|
||||||
|---|---|---|---|---|---|---|---|
| 0 h | 3 h
|
6 h
|
24 h
|
||||
| Recovery | Recovery | Reduction | Recovery | Reduction | Recovery | Reduction | |
| O35E (lung) | 112,489 (77,097-164,129) | 35,782 (23,721-53,977) | 68.2* | 18,480 (11,764-29,031) | 84.0* | 102 (50-211) | NDd |
| O35EkdtA (lung) | 63,400 (54,963-73,130) | 8,979 (7,861-10,256) | 86.0** | 1,771 (787-3,986) | 97.2** | <100 | ND |
| O35E (nasal washes) | 15,661 (12,596-19,470) | 4,662 (2,776-7,829) | 70.2* | 1,541 (1,104-2,149) | 90.1*** | 26 (11-61) | ND |
| O35EkdtA (nasal washes) | 14,614 (9,976-21,410) | 1,123 (659-1,912) | 92.3** | 101 (56-181) | 99.3**** | 4 (1-12) | ND |
a
Mice were challenged by aerosol with 10 ml of 1.24 × 109 CFU/ml O35E or 7.8 × 108 CFU/ml O35EkdtA.
b
Lung and nasal washes were collected for bacterial counts, and each time point represents a geometric mean bacterial CFU of six mice.
c
Compared with time point zero. * versus **, significant difference in bacterial reduction between O35E and O35EkdtA at P < 0.01. *** versus ****, significant difference at P < 0.05. The chi-square test was used for all comparisons.
d
ND, bacterial recoveries in some mice were under detectable level.