RESUMO
Uropathogenic Escherichia coli (UPEC) that cause urinary tract infections bind to target cells via several distinct paris of adhesins and receptors. In this study we determine the role of type 1 pili in interaction of UPEC with human neutrophils. Type 1 piliated and unpiliated strains (obtained by growth at a pilus-restrictive temperature) of UPEC were used for determining the effect of this adhesin on migration of neutrophils towards bacteria in Boyden chamber. The lectinophagocytosis and intracellular killing of bacteria with purified human neutrophils were estimated by counting of the number of viable bacteria in 45 min. The results indicate that type 1 piliated UPEC stimulated significantly greater chemotaxis than did unpiliated bacteria and bacteria in which the piliation was suppressed. Phagocytosis of type 1 piliated UPEC occurred in the direct and opsonin-independent manner. In contrast, unpiliated bacteria failed to bind to PMN.
