Thursday 20 November 2008

Neisseria menningitidis:

Bacterium


Neisseria meningitides, also known as meningococcus is classified as a gram negative diplococcus, meaning it stains red using the gram stain and appears as two round cells in pairs. This organism is best known for its ability to cause meningitis. Symptoms may include fatigue, fever, headache, neck stiffness to coma and death can occur in about 10% of the cases. There are several serotypes (can produce distinct antibodies in response to their invasion) and these my correlate with the geographical location one aquires the infection. Antibiotic treatment might include Cephalosporins, Erythromycin, Tetracycline or Ciprofloxacin.

The photo above is of a specimen obtained from a Lumbar Puncture (LP) where a fine needle is introduced into the spinal column in order to obtain some Cerebral Spinal Fluid (CSF). The fluid was processed in a cytospin centrifuge which concentrates the specimen onto a small spot on a microscope slide, flattening out any white cells present in the process while drawing off excess fluid. White cells may be polymorph nucleocytes or monocytes depending on the infecting agent. The white blood cells are the body’s immune response attempting to defend it from the invaders. The slide is then “fixed” to adhere the material to the slide and then stained by the “Gram” method. Neisseria meningitides will appear as single or “diplo” (two) red coloured cells, often within the white blood cells. x1000 Magnification under a light microscope