Light micrograph through human brain tissue showing purulent meningitis. Meningitis is described as inflammation of the lining around the brain and spinal cord, which can be serious if not treated quickly. Purulent meningitis refers to the inflammation of the leptomeninges (the two innermost layers of tissue that cover the brain and spinal cord) occurs along with infection of the subarachnoid space by various purulent bacteria. Clinically, purulent meningitis usually manifests as fever, vomiting, headache and meningeal irritation. Purulent meningitis due to the bacterium Rhodococcus equi is extremely rare.