Azithromycin resistance evolution in Neisseria gonorrhoeae

The prevalence of azithromycin resistance in Neisseria gonorrhoeae is increasing in a number of populations worldwide. To characterize the genetic pathways leading to high-level azithromycin resistance, a customized morbidostat was used to subject two N. gonorrhoeae reference strains (WHO-F and WHO-X) to dynamically sustained azithromycin pressure. Within 26 days, all cultures evolved high-level azithromycin resistance. We tracked stepwise evolution of resistance by whole genome sequencing.