Neisseria gonorrhoeae is a causative agent of Gonorrhea which is one of the sexually transmitted diseases. Gonorrhea is the second problem in epidemioloty of such diseases in Thailand. The provisional diagnosis depends on characteristic of discharges and Gram’s staining for intracellular gram negative diplococcic of polymorphonuclear cells. Gram’s staining and fluorescent antibody technique were determined directly from 100 specimens from the patients who attended to the Venereal Disease Clinic in Bhumipol Aduljadeh Hospital. The specimens were cultured on Thayer-Martin medium for isolation of N.gonorrhoeae and confirmed by gram’s stain, fluorescent antibody technique, sugar fermentation of maltose, glucose, and sucrose, and coagglutination test. The results from Gram’s stain were found intracellular gram negative diplococcic in 53 specimens and 50 positive results by fluorescent antibody technique. The difference between Gram’s stain and fluorescent antibody technique was 3% from 100 specimens. N.gonorrhoeae were isolated from 46 specimens and save the positive results in the confirmatory tests. All isolated strains gave the positive results to exidase reagent and coagglutination test. Only 44 isolated strains fermented glucose. Twenty-five strains of N. gonorrhoeae were sensitive to penicillin and twenty-one strains had resistance to penicillin. From the beta-lactamase test. Only 18 strains resisting penicillin were beta-lactamase producing strains. Thus, Gram’s staining is easier, more rapid and less expensive than fluorescent antibody technique for the routine laboratories.
