Identification of Neisseria gonorrhoeae in the routine venerelogical laboratory: Comparative study of coagglutination, direct immunofluorescence, and sugar fermentation reaction.

The coagglutination (CoA) method for the identification of Neisseria gonorrhoeae colonies grown on selective culture media was used on 116 strains in a routine venereological laboratory together with the direct immunofluorescence (IF) test and the sugar fermentation reaction. Correlation of results between the CoA method and the direct IF test and between the CoA test and the sugar fermentation reaction was 95.7% and 97% respectively. The sugar fermentation reaction requires subcultures and is more time-consuming than the IF test; the latter needs elaborate technical equipment and experience. The CoA method however can be carried out with the primary culture, is technically easy to perform and to reproduce, and the result is available within minutes.