Neisseria

Gram negative

diplococci with flattened sides

Cytochrome C Oxidase positive - phenylenediamine turns black, rapid test

They grow on Chocolate (not blood) agar with 5% CO2 atmosphere

VTCN agar (vancomycin, Trimethoprim, Colistin and Nystatin) or Thayer-Mrtin agar

Pili = antigenic variation

IgA protease

associated with MAC (C5-9) deficiency

Neisseria meningitidis

large capsule: latex particle agglutination

ferments Maltose

colonizes nasopharynx first; transmitted by respiratory secretions achieved by IgA protease

polysaccharide Capsules

Type B is not included in the vaccine (weakly immunogenic to make vaccine) so, Type B strain is the most common in the US

Vaccine: capsular polysaccharide of strains W-135, A, Y & C (WAY to prevent from Capsule)

Lipo-oligosaccharide (LOS) envelope proteins cause inflammatory response -> vascular leakage -> petechial rash/hemorrhage with thrombocytopenia

hypovolemia, shock and death

(Waterhouse-Friderichsen syndrome)