Identification of pathogenic neisseriae by genetic transformation

The detection of pathogenic neisseriae by genetic transformation of a naturally occurring proline auxotroph of Neisseria gonorrhoeae strain F62 is described. Of 169 clinical isolates of N. gonorrhoeae, approximately 90% gave a positive transformation assay. Twelve clinical isolates of N. meningitidis and stock cultures of the various meningococcal serogroups also gave a positive result. However, the sensitivity of the assay was found to be approximately 1000-fold lower with N. meningitidis as test organism. Eleven other members of the family Neisseriaceae failed to transform the recipient organism. Although proline requirement did not appear to limit the value of the assay greatly, it probably was the main reason for negative results. The sensitivity of the assay and its ability to detect non-viable gonococci suggests that this method merits further investigation as a possible aid to diagnosis of gonococcal infection in special circumstances.