Percentage of human serum stored at 22°C required to kill S. Typhimurium D23580 and anti-S. Typhimurium antibody levels in study sera.
Killing of bacteria by different percentages of freshly thawed serum from A. subject 1 and B. subject 2 at 45, 90 and 180 minutes in serum bactericidal assay using 106 cfu/ml S. Typhimurium D23580∶10% (red circles), 20% (green squares), 30% (blue triangles), 40% (purple diamonds) and 50% (orange inverted triangles) serum diluted with PBS, 100% PBS (black crosses), 100% fresh serum (pink vertical crosses) and 100% heat-inactivated serum (blue circle and dashed lines). Initial concentration of bacteria 106 cfu/ml with numbers of viable bacteria plotted against duration of assay. Killing of bacteria by different percentages of serum from C. subject 1 and D. subject 2 at 180 minutes following storage at 22°C. Change in viable count (cfu/ml) plotted against duration of time serum stored at 22°C. E. Levels of anti-S. Typhimurium D23580 IgG, IgA and IgM antibodies in human sera used in study as assessed by flow cytometry. F. Killing of bacteria by fresh serum (solid lines) and heat-inactivated serum (dashed lines) from subject 1 (red circles), 2 (green squares), 3 (blue triangles) and 4 (purple diamonds) at 45, 90 and 180 minutes.