FIG 7.
A periplasmic β-lactamase is present in C. rodentium OMVs. OMVs were isolated from various C. rodentium strains grown to mid-log phase with 50 μM FeCl2. OMVs were solubilized with 0.1% Triton X-100 and were incubated with the chromogenic substrate nitrocefin. Cleavage of nitrocefin was monitored for 20 min at 22°C by measuring the OD482. Data shown are representative of three independent experiments. Data were fitted to a Michaelis-Menten nonlinear regression curve using GraphPad Prism 7 software.