Epidemiology of resistance in Neisseria gonorrhoeae.

In the face of almost unique selective pressures many strains of gonococci have become increasingly resistant to antibiotics. Both chromosomal mutation and acquisition of plasmids are involved. However, whereas there have probably been multiple selections of many mutation events determining chromosomal resistance, evidence suggests that a very limited number of plasmid acquisitions has occurred, with subsequent spread within members of the species.