TABLE 3.

In vitro neutralization of alpha toxin activity

Antiserum and/or route of administrationaGMT95% CIbP valuec
GST-Cpa247-370d158.6154-1640.001
Naïve1.10.8-1.4>0.2
Oral
    PY791.150.75-1.8>0.2
    HT2303.83.0-4.60.001
    HT25119.913.8-36.10.02
    HT2669.58.4-10.60.001
Nasal
    PY791.30.8-1.6>0.2
    HT2303.73.0-17.70.001
    HT25110.36.9-13.70.001
    HT26610.59.4-11.60.001
  • a Serum (day 60) obtained from mice immunized as outlined in Fig. 2 was pooled and serially diluted, and aliquots were preadsorbed with 0.1 μg of alpha toxin. Preadsorbed mixtures were coincubated with mouse erythrocytes for 1 h, and hemolysis was measured. The end-point titer was defined as the dilution causing 50% hemolysis.

  • b CI, confidence interval.

  • c P value compared to PY79 and naïve control groups.

  • d Serum from mice immunized (i.p.) with 2 μg of pure GST-Cpa247-370 protein.