TABLE 2.

In vivo characterization of replacement mutants

MutantaLD50bAttenuation levelc
Respiratory tract infectionOtitis media infection
ΔCO20013.28WT
ΔHOI101>5.61-log unit decreaseWT; 3-log unit decrease in blood
ΔIPC0094.08WT
ΔIPC012>6.263.5-log unit decrease6 log units; undetectable in blood
ΔISIP4094.53∼1-log unit decreaseWT
ΔISIP4544.65∼WT
ΔISIP4564.84WT
ΔISIP485ND∼WT
ΔISIP4973.69∼WT
ΔISIP069ND∼WT
ΔISIP741ND∼WT
ΔISIP870ND∼WT
ΔOM001>5.974-log unit decrease6 log units; undetectable in blood
ΔRTI0062.521-log unit decreaseWT
ΔRTI0093.651-log unit decreaseWT
ΔSPIV0122.85WT
ΔSPIV013NDWT
ΔSPIV0145.791-log unit decreaseWT; 1-log unit decrease in blood
ΔSPIV0152.9WT
ΔSPIV0195.541-log unit decreaseWT; 4.5-log unit decrease in blood
ΔSTS001NDWT
ΔSTS004NDWT
ΔSTS008ND1.5 log units
ΔSTS0124.402.5-log unit decreaseWT
ΔSTS0183.652 log unitsWT
No./totals (%)14/25 (56)d11/25 (44)e2/25 (8)f
  • a Prefix indicates DFI screen in which clone was identified: CO2, carbon dioxide shift; HOI, high osmolarity; IPC, intraperitoneal chamber; ISIP, iron starvation; OM, otitis media infection; RTI and SPIV, respiratory tract infection; STS, static temperature shift.

  • b Represents the log value of the LD50. The LD50 of wild-type D39 is approximately 100 organisms. ND, not done.

  • c Denotes attenuation level compared to D39 (WT).

  • d Number of mutants with LD50 ≥10-fold higher than that of D39.

  • e Number of mutants colonizing lungs ≥10-fold less than D39.

  • f Number of mutants completely attenuated.