Interaction of Candida krusei with human neutrophils in vitro

In human neutrophil monolayer assays the percentage phagocytosis of Candida krusei by neutrophils was found to be significantly lower (9%) than that for C. albicans (37%). Both organisms required opsonisation with complement products for ingestion. The number of competent neutrophils phagocytosing C. krusei was increased with: antisera specific to C. albicans (49%); the neutrophil chemo-attractant formyl-methionyl-leucyl-phenylalanine (fmlp) (49%); mannan extracted from the cell wall of C. albicans (72%); and a crude cell extract from C. krusei (61%). In the case of C. albicans all but one of these methods increased the proportion of phagocytosing neutrophils per slide. The data provide evidence for differences in quantitative phagocytosis of C. krusei and C. albicans and suggest that C. krusei is resistant to phagocytosis in vitro.