FIG 7.

An S. Typhimurium ΔoxyR ΔiprA mutant strain displays a growth defect on solid medium. (A) S. Typhimurium χ3339 WT, ΔoxyR mutant, ΔiprA mutant, and ΔoxyR ΔiprA mutant strains were grown in liquid medium to equivalent OD₆₀₀ values, serially diluted, and plated on solid medium for colony growth. (B) Strain χ3339 ΔoxyR ΔiprA containing either vector or vector plus iprA was diluted and plated for single-colony growth on solid medium. (C) The solid medium was supplemented with catalase protein (140 μg per ml of medium), and the indicated strains were grown and plated as described for panel A.