FIG. 1.

(A) Association of Neisseria lactamica and Neisseria meningitidis with human meningioma cells. Confluent monolayers of meningothelial meningioma cells were challenged over time with various doses of bacteria, and total association to cells was quantified by viable counting. Infection experiments were carried out in triplicate with two different meningioma cell lines. Data are shown from typical experiments with meningioma cells from one patient, with individual points representing the mean bacterial CFU counts per 5 × 10⁴ cells in monolayer. The error bars represent the standard deviations from triplicate-infected wells. (B) Neisseria lactamica and Neisseria meningitidis do not invade meningioma cells. Confluent monolayers of meningothelial meningioma cells were challenged for 24 h with various doses of bacteria, and total association to cells was quantified by viable counting. Treatment with gentamicin was used to remove all extracellular bacteria. Cells were also pretreated with cytochalasin D prior to bacterial infection and then incubated with gentamicin after 24 h. Experiments were carried out in duplicate with meningioma cells from two different patients, and typical data are from one experiment with one patient cell line, with bars representing the mean bacterial CFU counts and the error bars representing the standard deviations from triplicate-infected wells.