FIG 9.

Intracellular glutathione levels in N. meningitidis with or without HBMEC infection. The intracellular glutathione concentration in N. meningitidis was measured as described in Materials and Methods. The glutathione concentration in bacteria is expressed as nanomoles of glutathione per milligram of bacterial protein. The error bars represent the standard deviations of the means from the results of at least four experiments. Statistical analyses were performed with a two-tailed Student t test; N.S., nonsignificant; *, P < 0.02; **, P < 0.005.