bacterial meningitis
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Bacterial Meningitis. Linnea Giovanelli. What Is Meningitis?. The three layers of the meninges Bacteria can reach the meninges through the bloodstream or direct contact. Inflammation of the meninges through bacterial spread in cerebrospinal fluid, CSF. - PowerPoint PPT PresentationTRANSCRIPT
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)