TABLE 2.

Resistance to antimicrobial peptides and the complement system

StrainMBC of protamine (μg/ml)Serum resistancea (% survival)
MO1015096.75 ± 6.50
MO10 ΔwaaL15099.15 ± 1.69
MO10 wbfF1503.68 ± 5.58
MO10 ΔwaaL ΔwbfF1500.03 ± 0.03
MO10 ΔgalEK1500.05 ± 0.06
MO10 ΔgalEK pACYCgalEND90.25 ± 11.84
MO10 waaFb75100 ± 0
MO10 waaF pACYCwaaF150ND
MO10 wavB15092.48 ± 8.68
  • a Serum resistance was calculated as the ratio of the number of CFU found after cells were incubated for 45 min in 20% normal human serum divided by the number of CFU found after cells were incubated for 45 min in 20% heat-inactivated normal human serum. Indicated is the mean ± standard deviation. All assays were performed at least four times. ND, not determined.

  • b This mutant was also tested in the presence of control plasmid pTrcAkan.