Columbia sheep agar plates

N. meningitidis and N. lactamica strains were grown on Columbia sheep agar plates (BioMerieux) at 37 °C, 5% CO₂ and water saturated atmosphere. Detailed information on the bacterial strains used in this study can be found in the Supplementary Table S1. To prepare inocula for experiments, bacteria were resuspended in RPMI medium (Life Technologies) and adjusted to an OD₆₀₀ of 1.0, which corresponded to 10⁹ CFU/ml for all strains, except for N. lactamica, which was adjusted to OD₆₀₀ of 2.0 to yield the same density. Serial dilutions were made in RPMI medium to obtain the required bacterial density for infection experiments; bacterial inocula were always verified by plating and colony enumeration.

N. meningitidis was grown on Columbia sheep agar plates (BioMérieux) at 37°C and 5% CO₂ in a water-saturated atmosphere. Strain MC58 was used for most experiments and belongs to serogroup B (type B:15:P1.7,16-2:F1-5; ST-74, ST-32 complex) (71 (link)). Its coisogenic mutants, MC58Δcsb (lacking capsule) and MC58Δcsb-GFP (expressing green fluorescent protein), and their respective plasmid constructs were described elsewhere (72 (link), 73 (link)). Further information on the N. meningitidis strains used in this study is available in Table S1 in the supplemental material.