Growth analysis

Strains were inoculated into 2mL of TSB from blood agar plates and incubated at 37°C for 6h. Cultures were then diluted 1:1000 in either 2mL of TSB (BD, Heidelberg, Germany), TSB +4% NaCl, RPMI 1640 (Gibco, Thermo Fisher Scientific), 70% heat-inactivated human serum (pooled from 18 healthy individuals, diluted with 30% phosphate-buffered saline), permission for the use of anonymous donations (WF-015/12) was obtained from the Ethical Committee of the Ärztekammer Hamburg (Germany), and synthetic nasal media (SNM3)[34], 200μl of the suspension were inoculated into 96-well flat-bottom plates (Greiner, Bio-One, Kremsmünster, Austria) and incubated for 22h at 37°C in an ELISA reader (Tecan infinite M200, Männedorf, Switzerland). OD₆₀₀ was automatically determined after brief agitation every 30min. Experiments were conducted in duplicates. Biological replicates were averaged for statistical analysis. Growth curve AUCs were determined in GraphPad Prism v5 (GraphPad Software, La Jolla, CA, USA).