Neisseria bacilliformis

Morphology

With the exceptions of N. elongata and N. weaveri, most members of the genus Neisseria have a cocci or diplococci cellular morphology. However, N. bacilliformis has a bacillus morphology measuring 0.6 μm by 1.3 μm to 3.0 μm. N. bacilliformis is nonmotile and it undergoes aerobic respiration. It stains Gram negative and has been successfully cultured on chocolate agar and sheep blood agar. No hemolysis has been observed. Growth has been documented on trypticase soy agar, but the size of the colonies are roughly half that of those cultured on chocolate agar and sheep blood agar. Growth has not been achieved on modified Thayer–Martin culture agar, the preferred media for culturing N. gonorrhoeae. Colonies are round, smooth, and have a light gray coloration. It tests positive for the oxidase test and negative for indole production. No acid is produced in the presence of dextrose, lactose, maltose, or sucrose. Some strains are capable of reducing nitrate and producing catalase. All strains that have been isolated thus far have shown susceptibility to antibiotics.