Loss of low-level antibiotic resistance in Neisseria gonorrhoeae due to env mutations.

Mutations (env) which resulted in increased sensitivity of gonococci to diverse compounds were studied by transformation. Strains carrying an env mutation were more sensitive than wild-type strains to several antibiotics, dyes, and detergents. The env mutations resulted in complete phenotypic suppression of low-level resistance to these same drugs determined by mutation at ery. Recombination was observed in transformation crosses between various env mutants. The env locus was not linked to the cluster of antibiotic resistance genes near str and spc.