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Bacterial Meningitis

Bacterial Meningitis

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Bacterial Meningitis

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  1. Bacterial Meningitis Linnea Giovanelli

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

  3. Bacterial Infection – Why Meningitis Is Difficult • Many species of bacteria can cause bacterial meningitis • Neisseria meningitidis • Haemophilusinfluenzae • Streptococcus pnemoniae • Listeria monocytogenes http://lib.jiangnan.edu.cn/ASM/032-Examination%20of%20Gram%20Stains%20of%20Spinal%20Fluid-Bacterial%20Meningitis-Introduce.htm

  4. 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

  5. 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

  6. Nesseriameningitidis • 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

  7. 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

  8. 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

  9. Diagnosis and Treatment

  10. Mortality Rate Dropped Sharply With Use of Antibiotics

  11. In the Developed World… • Current US case rates between 2003-2007 • Streptoccocuspneumoniaeremains 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

  12. 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

  13. Treatment procedures depend on causative bacteria Tunkel, A.R; Practice Guidelines for the Management of Bacterial Meningitis

  14. 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

  15. 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

  16. 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

  17. 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

  18. Vaccinations • Pnemoccocal vaccines also have two types – conjugate, PCV13 and polysaccharide, PPVSV • HiBVaccine • Recommended for all children under 5

  19. 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

  20. 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. Psychiatry2004, 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)