Meningitis is present when the membranes covering of the brain and spinal cord become swollen and inflamed. This covering is called the meninges.
Bacteria are one type of germ that may cause meningitis. Gram-negative bacteria are a type of bacteria that behave in a similar manner in the body. They turn pink when tested in the laboratory with a special stain called Gram stain.
This article covers Gram-negative meningitis caused by the following bacteria:
- Escherichia coli
- Klebsiella pneumoniae
- Pseudomonas aeruginosa
- Serratia marsescens
Gram-negative meningitis is more common in infants than adults. But it can also occur in adults, especially those with one or more risk factors. Risk factors in adults and children include:
Symptoms usually come on quickly, and may include:
- Fever and chills
- Mental status changes
- Nausea and vomiting
- Sensitivity to light (photophobia)
- Severe headache
- Stiff neck (meningismus)
- Symptoms of a bladder, kidney, intestine, or lung infection
Other symptoms that can occur with this disease:
Exams and Tests
The health care provider will perform a physical exam. Questions will focus on symptoms and possible exposure to someone who might have the same symptoms, such as a stiff neck and fever.
If the provider thinks meningitis is possible, a lumbar puncture (spinal tap) will likely be done to remove a sample of spinal fluid for testing.
Other tests that may be done include:
Antibiotics will be started as soon as possible. Ceftriaxone, ceftazidime, and cefepime are the most commonly used antibiotics for this type of meningitis. Other antibiotics may be given, depending on the type of bacteria.
If you have a spinal shunt, it may be removed.
The earlier treatment is started, the better the outcome.
Many people recover completely. But, many people have permanent brain damage or die of this type of meningitis. Young children and adults over age 50 have the highest risk for death. How well you do depends on:
- Your age
- How soon treatment is started
- Your overall health
When to Contact a Medical Professional
Call the local emergency number (such as 911) or go to an emergency room if you suspect meningitis in a young child who has the following symptoms:
- Feeding problems
- High-pitched cry
- Persistent unexplained fever
Call the local emergency number if you develop any of the serious symptoms listed above. Meningitis can quickly become a life-threatening illness.
Prompt treatment of related infections may reduce the risk of meningitis.
Nath A. Meningitis: bacterial, viral, and other. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 412.
Tunkel AR, Van de Beek D, Scheld WM. Acute meningitis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 89.
Review Date 7/31/2016
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA.Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.