sensitivity assay for 1529 Δspy1236 with the overexpression of htrA . H2O2 sensitivity assays were performed for 1529Δ spy1236 (pLZ-htrAforward) (a) or 1529Δ spy1236 (pLZ-htrAreverse) strains (b). Bacteria were grown in broth supplemented with 62.5 mg/mL kanamycin. H2O2 (61 mM) was added to 1-mL aliquots of culture grown to an OD660 of ~0.3. After 15 min at room temperature (~25°C), viable counts were performed as described in Figure 4. Values expressed are the means (± SEM) of three independent experiments.