Bactericidal activity of human serum against strains of Klebsiella from some pathogenic sources

Ten strains of K. pneumoniae were isolated from 225 cases of urinary tract infections, respiratory tract infections and diarrhea [4.4 percent]. They were tested for sensitivity to pooled normal human serum and viable counts were done at 0, 60, 120, 180 minutes. Normal human serum was obtained by pooling the sera from twenty healthy adults who were not receiving antibiotics. Five strains [50 percent] were sensitive to human serum, three strains [30 percent] were resistant to human serum and two strains [20 percent] showed intermediate sensitivity to human serum. Thus the presence of bactericidal action of normal serum on klebsiella may explain the low incidence [4.4 percent] of Klebsiella isolates from different clinical samples