AINs possess significantly higher phagocytotic and bactericidal activities than do GINs. (A) Phagocytotic and bactericidal activities against E coli infection were determined by the number of extracellular bacteria, phagocytized bacteria, recovered intracellular bacteria, and killed bacteria. There was a 1.26- ± 0.01-fold increase in bacterial numbers over the 45 minutes of the experiment (*GINs versus AINs, P < .03 at least). (B) Confocal fluorescence microscopy of surviving and dead bacteria in GINs, AINs and PBNs. White arrow indicates surviving (green) or dead bacteria (red), whereas black arrow indicates example of neutrophil nucleus stained in red simultaneously by PI fluorescent dye. Representative confocal fluorescence images of bacteria were reproduced at 60× magnification. (C) Quantification of both extracellular bacteria after infection and in situ killed bacteria in panel B (*GINs versus AINs or PBNs, P < .04 at least). (D-E) Similar to panels A and B, phagocytic and bactericidal activities against S aureus infection were determined in GINs, AINs, and PBNs (*GINs versus AINs, P < .04 at least). (F-H) Ultrastructural images of bacterial infection of GINs (F), AINs (G), and PBNs (H) with electron microscope. Lb indicates living bacteria; Db, suggestive of dead bacteria; Pg, primary granule; and Sg, secondary granule.