Neisseria gonorrhoeae (NG) exhibits high genome plasticity caused by an unusually high density and diversity of transposable elements, and easily performs various mechanisms of drug resistance. Here we investigated the i19.05 clinical isolate with reduced susceptibility to penicillin (MIC=0.5 mg/L), tetracycline (MIC=0.5 mg/L), and azithromycin (MIC=1.0 mg/L), which carried no known genetic resistance determinants except of penA, which cannot explain the expression of the resistant phenotype. In addition, it attracted our attention to the presence of a new and unique mutation of Asn105Ser in SurA and several mutations in Omp85 (BamA). The goal of our study was to search for new molecular mechanisms of drug resistance. The pan susceptible n01.08 NG clinical isolate was involved as a control to compare, as well as a recipient in transformation procedure. The fragments of i19.05 genome contained mutant surA, omp85, and penA genes were amplified and used in spot-transformation of the n01.08 recipient isolate as described (Ilina, 2013). Finally, a resistant transformant NG05 (PenAmut, Ompmut, SurAmut) was obtained. For comprehensive proteomic analysis via LC-MS/MS, the proteins from the all tested N. gonorrhoeae strains were fractionated on cell envelope (CE) (including outer membrane, periplasmic, inner membrane) and cytosol (C). A total of 1125 proteins in the CE fraction, of which 894 were common in all strains were identified. Proteomics of the C fraction in the same experiment yielded a total of 928 proteins, of which 676 were shared among all strains. Proteome coverage for both fractions ranged from 52.72% (1111 proteins) in n01.08 to 54.53% (1149 proteins) in i19.05.