Interactions of Neuropathogenic Escherichia coli K1 (RS218) and Its Derivatives Lacking Genomic Islands with Phagocytic Acanthamoeba castellanii and Nonphagocytic Brain Endothelial Cells

Figure 2

Escherichia coli K1-mediated human brain microvascular endothelial cell cytotoxicity was abolished with the deletion of RS218-derived genomic island 21. E. coli K1 strain E44 (10⁶ c.f.u.) was added to confluent cultures of primary human brain microvascular endothelial cells (HBMEC) grown in 24-well plates. Plates were incubated in a CO₂ incubator for 24 h. At the end of the incubation, supernatants were tested for LDH release and converted to percentage cell death as described in Section 2. Data represent the mean ± standard error of three independent experiments. Note that the deletion of RS218-derived genomic island 21 (RDI 21) abolished E. coli K1-mediated cytotoxicity.