The present invention is directed to a rapid enzymatic method using chromogenic substrates for the identification of Neisseria gonorrhoeae, Neisseria meningitidis and Neisseria lactamica. The assay correlated 100% in its identification of pathogenic Neisseria with modified NYC fermentation medium. The assay is more sensitive in its direction of prolylaminopeptidase activity in Neisseria meningitidis than any of the commercially available systems.
The test method of the present invention is performed by first applying a small amount of buffer, then applying colonial growth, to each of three test areas (PAP, GAP, and BDG) on filter paper test strips. The strips are then incubated at from about 35.degree.-37.degree. for 10 minutes or at room temperature for 20 minutes. If the BDG area is positive (blue-green color) the isolate is identified as Neisseria lactamica. If the BDG area is negative, a chromogenic reagent, such as dimethylaminocinnaminaldehyde, is added to the PAP and GAP test areas. If a purple color develops in area B. N. meningitidis is present; however, if a red color develops solely in area C the presence of Neisseria gonorrhoeae is indicated.