So being a micro-organism that got a plasmid that give you resistance to an antibiotic would be a good thing - that gave you resistance to something that naturally killed cells like you in your environment would be a good thing.

假如一个微生物,因含有质粒而具有抗生素抗性,这实在是一桩美事--,在同样的环境下,普通细胞会被杀死,而你们这些具有抗性的细胞却安然无恙,这实在太棒了

耶鲁公开课 - 生物医学工程探索课程节选