FIG 4.

Influence of NMB2132 (NHBA), NMB1030, NMB2095 (ACP), and NMB1969 (NalP) on temperature-dependent N. meningitidis phenotypes. Deletion mutants of the indicated genes were generated in N. meningitidis MC58 or its capsule-deficient derivative MC58Δcsb as indicated above each plot. (A) Autoaggregation was determined as decreases in the OD₆₀₀ of meniscal samples taken at 0 min and 30 min from nonagitated liquid cultures. (B) Early biofilm formation of parental N. meningitidis MC58Δcsb and corresponding mutants grown at either 32°C or 37°C as indicated below the x axis. (C) Adherence of N. meningitidis MC58 and corresponding mutants to Detroit nasopharyngeal epithelial cells was tested by infecting 5 × 10⁵ Detroit cells with 10⁷ CFU N. meningitidis per well. Adherent bacteria were enumerated after 1 h of incubation by plating serial dilutions on Columbia blood agar. (A to C) Mean values ± standard deviations (SD) from at least three independent experiments are shown. ***, **, and * refer to P < 0.001, P < 0.01, and P < 0.05, respectively, in one-way ANOVA applying Dunnett's post hoc test for comparing all groups to the corresponding parental strain at 37°C at 30 min (A) or to the parental strain at 32°C (B and C).