Possibility of Saccharide-Binding Protein to Interactions of Acanthamoeba castellanii and Several Bacteria

The ability of Acanthamoeba castellanii to ingest bacteria means suggests the presence of a mechanism of contact dependence. It has been confirmed that it is important to induce toxicity to target cells through lectin, a glycoprotein, with the strong pathogenicity of amoeba. In this study, it was analyzed the interaction between pathogenic bacteria and A. castellanii trophozoites and cysts using various concentrations of a monosaccharide called mannose. When the concentration of mannose was increased to 100 mM, the association of methicillin-resistant Staphylococcus aureus (MRSA) was reduced by more than 2 times. Moreover, it was confirmed that the number of MRSA reduced by about 80 times could invade A. castellanii trophozoites with 100 mM mannose. The association of Enterococcus faecalis with A. castellanii trophozoites was approximately 41% lower and the invasion of E. faecalis into A. castellanii trophozoites was reduced by about 2 to 60 times compared to the bacterial association, and E. faecalis never survived within the A. castellanii trophozoites. Interestingly, survival of Pseudomonas aeruginosa within A. castellanii trophozoites was reduced by 20 times but was significantly higher than that of other bacteria. The invasion or survival of P. aeruginosa was 0% in all results of A. castellanii cyst. The mechanism of contact dependence via monosaccharide-binding proteins other than mannose in A. castellanii is not only a way to inhibit A. castellanii, but also an analysis of the interaction.