Effects of preventive antibiotics on neutrophil phagocytosis as measured by the nitroblue tetrazolium dye test.

White blood cell counts and nitroblue tetrazolium dye tests were performed in three groups of dogs before and after the injection of Escherichia coli using colistimethate sodium and cephalothin sodium in the second and third groups, respectively, prior to the induction of sepsis. The response was a diminished white blood count and increased nitroblue tetrazolium dye test percentage in all groups. When antibiotic administration was performed prior to the induction of sepsis, the increase in the nitroblue tetrazolium reduction dye test was much more evident despite the overwhelming dose of bacteria given, suggesting that antibiotics given preoperatively will prevent the toxic effects of bacteria on the neutrophil and will enhance the phagocytic activity of the neutrophil.