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 h3 h6 h24 h
RecoveryRecoveryReductionRecoveryReductionRecoveryReduction
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**<100ND
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.