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Bacterial
Meningitis
Linnea 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.h
tml
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/032Examination%20of%20Gram%20Stains%20of%20Spinal%20FluidBacterial%20Meningitis-Introduce.htm
Different Ages Have Different
Risks

Newborns


Infants and Children


S. pneumoniae, N. meningitidis, H. influenzae
type b
Adolescents and Young Adults


Group B Streptococcus (GBS), E. coli, L.
monocytogenes
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
pathogenic
CSF 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
stage:



Seizures
Coma
Death
or late-
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/M87405
91-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 Drugresistant 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)