15.6
Antibiotic Selection
Antibiotic selection is typically used to ensure that a bacterial colony contains a plasmid with a few key features, an antibiotic resistance gene and a gene of interest that a researcher wants to express.
For the bacteria to uptake the plasmid, both must be incubated together and then, undergo heat shock to promote incorporation. Not every bacterium will successfully uptake a copy of the plasmid.
As the goal is to isolate bacteria that possess a copy, researchers add some of the bacterial culture onto a plate containing an antibiotic. Only those bacteria that have taken up the plasmid, which contains the resistance gene, will be able to degrade the antibiotic and grow on the plate.
Over the next few days, single bacterium will form colonies, which can then be selected for further work.
研究人员使用抗生素抗性基因来鉴定具有包含其感兴趣基因的质粒的细菌。当自发的DNA突变在细菌基因中产生改变以消除抗生素活性时，自然就会产生抗药性。细菌可以与其后代和其它细菌共享这些新的抗性基因。随着耐药菌和多重耐药菌的不断发展，抗生素的过度使用和滥用已造成了公共卫生危机。