Neisseria meningitidis. Coloured transmission electron micrograph (TEM) of a section through Neisseria meningitidis bacteria, the cause of bacterial meningitis. These non-motile Gram- negative cocci (spherical bacteria) occur as two cells (blue) in a capsule (green). The lower of the two has undergone mitotic division. Neisseria meningitidis is an obligate human parasite. It causes meningococcal meningitis, the inflammation of connective tissue membranes lining the brain and spinal cord. Symptoms include headache, fever, stiff neck, vomiting, delirium, sometimes death. Treatment is with antibiotics. Magnification: x28,000 at 6x7cm size.