False-colour transmission electron micrograph of Neisseria meningitidis, a spherical bacterium which causes meningitis in humans. The blebs surrounding the cell wall here are extra cellular material shed by the bacterium. 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: x15,850 at 6x4.5cm size