Ch. 21: Microbial Diseases of the Nervous System

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Ch. 21 Microbial Diseases of the Nervous System

• Structure and function of nervous system
• Bacterial diseases of the nervous system
• Bacterial meningitis
• Tetanus
• Botulism
• Leprosy
• Viral diseases of the nervous system
• Viral meningitis
• Poliomyelitis
• Rabies
• Arboviral encephalitis

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Structure and function of nervous system

• Central Nervous System
• Brain
• Spinal cord
• Peripheral Nervous System
• Cranial nerves
• Spinal nerves

Covered by meninges
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Bacterial meningitis

• Haemophilus influenzae
• Neisseria meningitidis
• Streptococcal groups
• Streptococcus agalactiae newborn meningitis
• Streptococcus pneumoniae
• Listeria monocytogenes

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Five leading causes of meningitis
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Haemophilus influenzae Meningitis

• Occurs mostly in children (6 months to 4 years)
• Gram-negative aerobic bacteria, normal throat
  microbiota
• Capsule antigen type b
• Prevented by Hib vaccine

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Meningococcal Meningitis

• N. meningitidis
• Gram-negative aerobic cocci, capsule
• 10 of people are healthy nasopharyngeal carriers
• Begins as throat infection, rash
• Serotype B is most common in the U.S.
• Vaccine against some serotypes is available

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Meningococcal Meningitis
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Streptococcus agalactiae

• Group B streptococci
• Capsule component causes virulence
• Newborn meningitis
• bacteria colonizes vagina of pregnant women
• baby aquires infection from mothers genital
  tract
• AAP now recommends women be tested late in their
  pregnancy positive results can be treated with
  antibacterial medication before labor

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Pneumococcal Meningitis

• Gram-positive diplococci
• 70 of people are healthy nasopharyngeal carriers
• Most common in children
• (1 month to 4 years)
• Mortality 30 in children, 80 in elderly
• Prevented by vaccination

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Listeriosis

• Gram-negative aerobic rod
• Usually foodborne, can be transmitted to fetus
• Reproduce in phagocytes

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Listeriosis
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Tetanus (Lockjaw)
Clostridium tetani
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Features of Tetanus (Lockjaw)
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Botulism (food-borne)
Clostridium botulinum
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Features of botulism
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Hansens Disease, Leprosy
Figure 22.8
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Hansens Disease, Leprosy
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Viral meningitis
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Poliomyelitis, Polio
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Poliomyelitis
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Rabies
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Rabies
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Arboviral encephalitis