Figure 3From: Physiologic cold shock of Moraxella catarrhalisaffects the expression of genes involved in the iron acquisition, serum resistance and immune evasionIncrease in the binding of transferrin on the surface of M. catarrhalis as a result of cold shock. A, strain O35E and its isogenic mutant O35E.tbpB exposed to 26°C or 37°C for 3 h were incubated with fluorescein isothiocyanate (FITC)-conjugated transferrin (0.1 μg/mL) and flow cytometry analysis was performed. Shown are representative flow cytometry profiles of strain O35E and O35E.tbpB after exposure at 26°C (gray) or at 37°C (black), which demonstrate that TbpB is required for maximum binding of transferrin on the surface of cold shock-induced Moraxella catarrhalis. The dotted line represents the negative control (bacteria only). The mean fluorescence intensity ± 1 standard deviation for three experiments performed is shown in panel B. *, P< 0.05 for 26°C versus 37°C (one-way analysis of variance).Back to article page