A small fraction of S. Typhimurium is tolerant to conditions that mimic stressors associated with infection.

Bacteria were grown to late log phase in LB and exposed to antibiotics (A) ampicillin, 100 μg/mL, (B) ciprofloxacin, 0.2 μg/mL, (C) polymyxin B, 5 μg/mL, (D) hydrogen peroxide, 1.25 mM, (E) pH 2.6–4.4, or (F) dipyridyl, 0–30 mM. Bacteria were monitored thereafter for survival by plating to LB-agar plates and enumerating CFU. Mean of > 4 independent experiments are shown; error bars denote SEM.将细菌在LB培养基中培养至对数生长后期，随后分别施加以下胁迫处理：(A) 氨苄青霉素（100 μg/mL）、(B) 环丙沙星（0.2 μg/mL）、(C) 多粘菌素B（5 μg/mL）、(D) 过氧化氢（1.25 mM）、(E) pH 2.6~4.4的环境，或(F) 联吡啶（0~30 mM）。后续通过涂布LB琼脂平板并计数菌落形成单位（CFU, Colony-Forming Unit）以监测细菌存活率。图中展示了超过4次独立重复实验的平均值；误差棒代表标准误（SEM, Standard Error of the Mean）。