Bacterial MeningitisLinnea Giovanelli

What Is Meningitis?

Inflammation of the meninges through bacterial spread in cerebrospinal fluid, CSF

The three layers of the meninges

Bacteria can reach the meninges through the bloodstream or direct contact

http://training.seer.cancer.gov/brain/tumors/anatomy/meninges.html

Bacterial Infection – Why Meningitis Is Difficult Many species of bacteria can cause

bacterial meningitis Neisseria meningitidis Haemophilus influenzae Streptococcus pnemoniae Listeria monocytogenes

http://lib.jiangnan.edu.cn/ASM/032-Examination%20of%20Gram%20Stains%20of%20Spinal%20Fluid-Bacterial%20Meningitis-Introduce.htm

Different Ages Have Different Risks

Newborns Group B Streptococcus (GBS), E. coli, L.

monocytogenes Infants and Children

S. pneumoniae, N. meningitidis, H. influenzae type b

Adolescents and Young Adults N. meningitidis, S. pneumoniae

Older Adults S. pneumoniae, N. meningitidis, L. monocytogenes

Transmission and Incubation Bacteria is largely carried in the nose

and throat of humans Most people carry these colonies

Bacteria are about as contagious as the flu or common cold L. monocytogenes is spread through

contaminated food Incubation usually lasts about four days

but can be as long as ten

Nesseria meningitidis Gram negative anaerobe Iron reduction is a

necessary part of metabolism

12 total serogroups Types A, B, C, Y and W135 Specific capsular proteins A and B are most

pathogenicCSF culture of N. meningitidis

N. meningitidis Antiphagocytic polysaccharide

capsule Lives and replicates inside

cytoplasm of neutrophils Major toxin is

lipooligosaccharide, LOS LOS has been shown to suppress

leukotriene B4 synthesis

http://lipidlibrary.aocs.org/lipids/lipidA/Figure1.png

SYMPTOMS Always exhibit:

Fever Headache Neck stiffness

And may exhibit one or more of the following: Altered mental state Nausea, vomiting Photophobia

Untreated or late-stage: Seizures Coma Death

Diagnosis and Treatment

Mortality Rate Dropped Sharply With Use of Antibiotics

In the Developed World… Current US case rates between 2003-2007

Streptoccocus pneumoniae remains the leading cause of death

Risk has decreased for children, but the rates of infection in infants under 2 months has remained the same

WHO estimates that bacterial meningitis causes around 170,000 deaths/year worldwide

Diagnostic Methods Clinical Analysis

Patient presents with typical symptoms – bacterial meningitis is suspected when other causatives are ruled out

Laboratory Analysis Lumbar puncture to produce cerebrospinal

fluid, CSF Gram stain of CSF Culture of CSF Identification of bacterial antigen

Treatment procedures depend on causative bacteria

Tunkel, A.R; Practice Guidelines for the Management of Bacterial Meningitis

Cephalosporins – 3rd Generation

β-lactam antibiotics Derived from fungus Acremonium

Similar in structure and action to penicillin

Each generation has increasing activity against Gram negative bacteria and decreasing activity against Gram positive

Acremonium (cultured)http://www.sciencephoto.com/image/297092/530wm/M8740591-Cultured_Acremonium_fungus-SPL.jpg

β-Lactam

Core of several antibiotics like penicillin and cephalosporins

Attack peptioglycans in bacterial cell walls Inhibition of cell wall synthesis

Resistance forms when bacteria develop β-lactamase

Resistance Pneumococcal

meningitis has shown increasing rates of penicillin resistance

Mildly resistant strains to other popular drugs are emerging

Cephalosporin resistance is not common R groups can be

changed – many variations

Vaccinations - Meningococcal Active against types A, C, Y and W-135

Two vaccines available in the US, a polysaccharide and a conjugate

Conjugate vaccine Strongly recommended for 11-21 years old Boosters needed after five years 85-100% effective

No vaccine for type B

Vaccinations Pnemoccocal vaccines also have two types –

conjugate, PCV13 and polysaccharide, PPVSV HiB Vaccine

Recommended for all children under 5

Vaccinations in the Developing World International

Coordinating Group (ICG)on Vaccine Provision for Epidemic Meningitis Control

Established in 1997 Coordinate

meningitis vaccine distribution

Vaccination clinic

http://www.who.int/csr/disease/meningococcal/icg/en/index.html

References http://www.nlm.nih.gov/medlineplus/ency/article/000680.htm http://www.cdc.gov/meningitis/bacterial.html http://www.who.int/nuvi/meningitis/en/index.html http://

www.merckmanuals.com/home/brain_spinal_cord_and_nerve_disorders/meningitis/acute_bacterial_meningitis.html

https://www.qiagen.com/geneglobe/pathwayview.aspx?pathwayID=50 http://textbookofbacteriology.net/neisseria_6.html Nester, E.; Anderson, D.; Roberts, C.E.; Microbiology: A Human Perspective.

McGraw Hill Higher Education, 7th ed., 2012. Hameed, N.; Tunkel, A. R.; Curr. Infect. Dis. Rep. 2010, 12, 274. (Treatment of

Drug-resistant Pneumococcal Meningitis) Gold, R.; Infect. Dis. Clin. North Am. 1999, 13, 515. (Epidemiology of bacterial

meningitis) Swartz, M. N.; N. Eng. J. Med. 2004, 351, 1826. (Bacterial Meningitis – A View of

the Past 90 Years) Ginsberg, L. J. Neurol. Neurosurg. Psychiatry 2004, 75. (Difficult and Recurrent

Meningitis) Tunkel, A. R.; Hartman, B. J.; Sheldon, L. K.; et al. Clin. Infect. Dis. 2004, 39,

1267. (Practice Guidelines for the Management of Bacterial Meningitis) Thiqpen, M. C.; Whitney, C. G.; Messonnier, N. E.; Zell, E. R.; et al. N. Engl. J.

Med. 2011, 26, 2016. (Bacterial Meningitis in the United States, 1998-2007)