title: Superoxol and amylase inhibition tests for distinguishing gonococcal and nongonococcal cultures growing on selective media.
abstract: Two inexpensive screening tests were evaluated singly and in tandem for distinguishing Neisseria gonorrhoeae from other oxidase-positive microorganisms growing on selective gonococcal media. In tests of 728 cultures, including 460 N. gonorrhoeae, 4 Neisseria lactamica, 257 Neisseria meningitidis, and 7 Branhamella catarrhalis, both Superoxol (30% H2O2; J. T. Baker Chemical Co., Phillipsburg, N.J.) and amylase inhibition tests were 100% sensitive (positive) for 20-h cultures of N. gonorrhoeae. Singly, the Superoxol test was 92.7% specific for N. gonorrhoeae, compared with a specificity of 82.3% for the amylase inhibition test. By using tandem screening tests to distinguish gonococci, we achieved an overall specificity of 98.6%. Group A meningococci were the primary source of error in the Superoxol test, with 97% (37 of 38) strains producing gonococcal like reactions for catalase. From 5 to 20% of N. meningitidis serogroups X, Y, Z, and Z' and nontypable strains, as well as about 50% of B. catarrhalis and N. lactamica strains, were also strong catalase producers.
mesh_terms: D000681:Amylases / Q000037:antagonists & inhibitors*; D001431:Bacteriological Techniques; D003470:Culture Media; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D009343:Neisseria / Q000145:classification* / Q000187:drug effects / Q000201:enzymology; D009344:Neisseria gonorrhoeae / Q000145:classification / Q000187:drug effects / Q000201:enzymology; D009345:Neisseria meningitidis / Q000145:classification / Q000187:drug effects / Q000201:enzymology; D009346:Neisseriaceae / Q000145:classification / Q000187:drug effects / Q000201:enzymology
chemical_list: D003470:Culture Media; D006861:Hydrogen Peroxide; D000681:Amylases