FIG 1.

Five regulators are required for full NO˙ resistance in multiple strains of S. aureus (SA). (A) Mutations in S. aureus transposon mutants identified as sensitive to NO˙ in the initial screen were transduced back into S. aureus JE2 as well as into S. aureus COL and Newman. The transduced strains were screened for NO˙ sensitivity when exposed to 5 mM DETA-NO at inoculation. The lag time (time to OD₆₅₀ of 0.2) for each NO˙-exposed strain was normalized to the lag time for the strain under aerobic conditions. Graphs depict the ratio of mutant to WT lag times (n = 3; error bars show the standard error of the mean [SEM]). (B) Mutants with deletions in the five most broadly NO˙-sensitive regulators constructed in S. aureus Newman were grown in LBGT either with or without the addition of 5 mM DETA-NO (n = 3; error bars show SEM). (C) Mutant-to-WT lag time ratios of the NO˙-exposed Newman strains (depicted in panel B) normalized to their respective aerobic lag times (n = 3; error bars show SEM). Significance was calculated using Student's two-sided t test to compare the normalized mutant lag time to the normalized WT lag time (*, significantly different from the WT; P ≤ 0.05).