Abstract: Obejective To study the effect of peritoneal macrophages of BALB/c mice on phagocytosis of Penicillium marneffei in yeast phase.Methods Yeast-phase P.marneffei and peritoneal macrophages of BALB/c mice were cultured both in vitro and in vivo.The number of colony forming unit (CFU) was counted at 60 min,120 min,240 min and 360 min respectively.The difference of the CFU numbers between the in vitro and in vivo groups was then analyzed.Calcofluor white stain was applied to observe the morphology of yeast cells.Results CFU numbers in four time points in each group differed significantly (P<0.05),while the difference of CFU numbers between the in vitro and in vivo groups showed no significance (P>0.05).P.marneffei in yeast phase showed light blue by calcofluor white stain under fluorescence microscope.Conclusions No obvious destroy or lysis exists in P.marneffei when co-cultured with macrophages.Calcofluor white stain is preferred for identification of macrophage and yeast cells.

Key words: macrophage, Penicillium marneffei, colony forming unit, calcofluor white stain