Table 2.

Mortality of burned mice infected with P. aeruginosa PAO1 and quorum-sensing mutant strains

StrainNo. of mice dead/total (% mortality)aAvg % mortalityb
Expt 1Expt 2Expt 3
PAO17/7 (100)5/6 (83.3)6/6 (100)94.3
PAO-R12/5 (40)1/4 (25)1/5 (20)28.3
PDO1002/5 (40)3/5 (60)2/5 (40)46.7
JP13/5 (60)2/5 (40)2/5 (40)46.7
JP2/pSW200c0/5 (0)1/5 (20)0/5 (0)6.7
  • a A total of 2 × 102 to 3 × 102 CFU of each strain was injected subcutaneously at the burn site immediately after burning. The mice were burned and then inoculated with each strain as described in Materials and Methods. The mortality among mice infected with each strain was determined at 48 h post burn infection as previously described (34). Three separate experiments were conducted with each strain.

  • b The average percent mortality of three independent experiments is shown.

  • c Plasmid pSW200 is a cloning vector (Table 1). Strain JP2/pSW200 was used as a negative control for other complementation studies (see Table 3). The presence of pSW200 in JP2 had no effect on its in vivo virulence.