False-colour transmission electron micrograph of Neisseria meningitidis, spherical bacteria which cause meningitis in humans. The pink area within the bacterium is genetic material. The bacteria are typically seen in pairs, each one concave on the side facing its partner. Meningitis is an inflammation of the meninges, the membranes enclosing the brain and spinal cord. Symptoms include intense headache, fever, loss of appetite, intolerance of light and sound, muscle rigidity and, in severe cases, convulsions, vomiting and delirium leading to death. Bacterial meningitis is treated with antibiotics or sulphonamides. Magnification: x28,800 at 6x4.5cm size