Escherichia coli meningitis commonly occurs in the neonatal period, but the basis of this age dependency is unclear. We have previously identified two types of E. coli-brain microvascular endothelial cell (BR IEC) interactions contributing to E. coli traversal of the blood-brain barrier (i.e., binding and invasion). The present study examined whether the age dependency off. call meningitis stemmed from differences in the capacities of neonatal and adult BMECs to interact dth E. call. BMECs were isolated from rats of different ages (10 days, 20 days and 3 months) as well as from humans of different ages (fetuses, 4- to 7-year-old children, and a 35-year-old adult, and 60- to 85-year-old geriatrics). The bindings off. call to young and old rat BMECs were similar, Also, the abilities of E. call to invade BMECs were similar for BMECs derived from young and old rats and from human fetuses, children, adults, and geriatrics. These findings suggest that the predominance of E. coli meningitis in neonates is not likely due to greater binding and invasion capacities of newborn compared to adult BMECs.