Identification of Neisseria gonorrhoeae with the ORTHOProbe DNA probe test

We evaluated and compared the ORTHOProbe DNA hybridization test (Ortho Diagnostic Systems, Inc., Raritan, NJ) with conventional carbohydrate fermentation and commercial rapid tests for identifying gonococci (GC). The ORTHOProbe system employs a biotinylated DNA probe that hybridizes specifically with chromosomal target sequences of GC. Hybridization is detectable visually following the addition of a streptavidin-peroxidase conjugate in a rapid 10-min. assay. A total of 200 clinical isolates resembling Neisseria (gram-negative, oxidase-positive diplococci) cultured from various sites were tested. The ORTHOProbe test reacted strongly with all GC (94) and not with nongonococcal organisms (106), yielding a sensitivity and specificity of 100%. The ORTHOProbe system provides a convenient and reliable test for identifying Neisseria gonorrhoeae.