Bacterial defenses against natural antibiotics promote collateral resilience to clinical antibiotics. Bacterial defenses against natural antibiotics promote collateral resilience to clinical antibiotics

To characterize the defense mechanisms P. aeruginosa has evolved in response to its most toxic phenazine, pyocyanin, we performed a genome-wide transposon sequencing (TnSeq) screen in which the mutant library was exposed to PYO under carbon starvation in order to maximize PYO toxicity, and genes for which transposon mutants were significantly enriched or depleted were identified. Overall design: Assessment of transposon mutant frequency per gene in a pooled library of approximately 145,000 random Tn5 transposon insertion mutants, following exposure to 100 µM pyocyanin for 26 hours in the absence of a carbon source, or to the same conditions without pyocyanin. The experiment was performed with two biological replicates.

为了表征铜绿假单胞菌（P. aeruginosa）针对其毒性最强的吩嗪类物质——绿脓菌素（pyocyanin, PYO）所演化出的防御机制，我们开展了全基因组转座子测序（genome-wide transposon sequencing, TnSeq）筛选实验。实验中将突变体文库置于碳源饥饿环境中暴露于PYO，以最大化PYO的毒性，进而筛选出转座子突变体发生显著富集或缺失的基因。
整体实验设计：在包含约145,000个随机Tn5转座子插入突变体的混合文库中，分别对两组样本进行处理——一组在无碳源条件下以100 µM绿脓菌素处理26小时，另一组施加相同条件但不含绿脓菌素作为对照，随后检测每个基因对应的转座子突变体频率。本实验设置了两次生物学重复。