DefinitionGram-negative meningitis is an infection of the membranes covering the brain and spinal cord (meninges) caused by bacteria that turn pink when exposed to a special stain (gram-negative bacteria).See also:Aseptic meningitisMeningitis - cryptococcalMeningitis -nullH. influenzaeMeningitis - meningococcalMeningitis - pneumococcalMeningitis - staphylococcalMeningitis - tuberculousAlternative NamesGram-negative meningitisCauses, incidence, and risk factorsAcute bacterial meningitis can be caused by gram-negative bacteria. Bacteria causing gram-negative meningitis include:Acinetobacter baumanniiEnterobacter aerogenesEscherichia coliKlebsiella pneumoniaePseudomonas aeruginosaGram-negative meningitis is much more common in infants than adults.Risk factors in adults and children include:Lo