Simplified complete medium for the growth of Neisseria gonorrhoeae

A complete medium for the growth of Neisseria gonorrhoeae has been developed, using the same basic ingredients contained in commercial media but with fewer supplements. Based on a comparison of plating efficiencies, this medium (designated TTU Complete Medium) supported the growth of laboratory strains of N. gonorrhoeae equal to that obtained on commercial GC agar base medium supplemented with Iso VitaleX. It was also equivalent to the commercial medium in supporting the growth of 67 clinical isolates and 6 auxotypes of N. gonorrhoeae when tested by the streak plate method. Based on turbidity measurements and viable plate counts, the liquid equivalent of TTU Complete Medium supported maximal growth yields of N. gonorrhoeae. The toxicity of different brands of agar appeared to be a major factor in preventing the growth of N. gonorrhoeae strains on solid media. The addition of starch neutralized the toxicity of some types of agar but not of others.