Neisseria meningitidis Characteristics:
Gram-negative intra cellular diplococci.
Present in the nasopharynx in 5-10% of healthy people.
Fig. 3.5 Neisseria meningitidis
Antigenic structure: . Capsular carbohydrate It is important for serogrouping of meningococci and there are 13 serogroups. The most important serogroups associated with disease in humans are A, B, C, Y and W135.