- It is a gram negative, non-motile cocci arranged in pairs called as diplococci.
- Neisseria are aerobic, non-sporulating, oxidase positive cocci.
- Neisseria meningitidis causes cerebrospinal fever that is Meningococcal meningitis.
1. Morphological characters
- They are gram negative,spherical shape cocci with flattened adjacent side.
- Its size ranges from 0.6-0.8 micrometer.
- Its size,shape and staining properties changes as the incubation period increases.
- Fresh culture cells are capsulated and as the culture becomes old its capsule disappears.
2. Cultural characters
- Meningococci requires enriched media for its growth.
- The growth media should be enriched with blood or serum.
- Selective media like blood agar, chocolate agar, Mueller-Hinton starch casein agar are commonly used.
- The optimum temperature required for its growth is 36°C and optimum pH is 7.5-7.6
- The colonies are small in size bluish grey coloured and convex in elevation.