LIGASE CHAIN-REACTION FOR DETECTION OF NEISSERIA-GONORRHOEAE IN UROGENITAL SWABS

The ligase chain reaction (LCR) is an in vitro nucleic acid amplificat ion technique that exponentially amplifies targeted DNA sequences, In a multicenter study, we evaluated the use of a 4-h LCR-based assay for the diagnosis of Neisseria gonorrhoeae infection of the cervix and ma le urethra. The LCR results were compared with those of culture for N. gonorrhoeae by using selective media, This assay amplifies target seq uences within the N, gonorrhoeae opacity gene, Discordant LCR-positive and culture negative specimens were further evaluated by testing by a nother LCR assay which used N. gonorrhoeae-specific pilin probe sets. A total of 1,539 female endocervical specimens and 808 male urethral s wab specimens were evaluated in the study. An expanded ''gold standard '' was defined to include all culture-positive as well as culture-nega tive, confirmed LCR-positive specimens, After resolution of discrepant samples, the sensitivities of the N. gonorrhoeae LCR assays for the f emale and male specimens were 97.3 and 98.5%, respectively, with speci ficities of 99.6 and 99.8%, respectively. Resolved culture sensitiviti es were 83.9 and 96.5% for the female and male specimens, respectively , The LCR assay for gonorrhea is a rapid, highly sensitive nonculture method for detecting gonococcal infection of the cervix and male ureth ra.