...1977;86:313. Classic. Mycoplasma hominis</oes not appear to be a major cause of NGU. Jacobs NF Jr, Kraus SJ. Gonococcal and nongonococcal urethritis...clinical and laboratory differentiation. Ann Intern Med 1975;82:7. Gram's stain is highly sensitive in the diagnosis of gonococcal urethritis and NGU. Judson...