TABLE 2.

Growth in human serum and complement susceptibility of P. gingivalis ATCC 33277 and gingipain-deficient mutants

StrainGrowth (OD660a/doubling time [h])% Viability inb:
Serum + heminSerum + hemin + casein hydrolysateSerumInactivated serum
ATCC 332770.33/40.57/3.887 ± 1192 ± 7
KDP131 (rgpA)NSGc0.56/5.4NDdND
KDP132 (rgpB)0.16/9.30.48/4.2NDND
KDP129 (kgp)NSG0.45/5.122 ± 9*72 ± 12
KDP112 (rgpA rgpB)NSG0.56/4.828 ± 14*82 ± 10
KDP128 (rgpA rgpB kgp)NSG0.48/6.70*0*
  • a OD obtained after 36 h of growth.

  • b Percent viability after the 2-h treatment was calculated as a function of the viable counts obtained with the time zero samples. Shown are means ± standard deviations of three independent experiments. The asterisks indicate a significant difference with respect to the wild-type strain (P < 0.005).

  • c NSG, no significant growth.

  • d ND, not determined.