Chapter 22: Microbial Diseases of Nervous System Flashcards
What is meningitis?
Inflammation of the meninges
What is encephalitis?
Inflammation of the brain
What are the four bacteria that commonly cause meningitis?
- Streptococcus pneumonia
- Neisseria meningitidis
- Haemophilus influenza type B (Hib)
- Listeria monocytogenes
What are some of the characteristics that these different pathogens have in common?
most have capsule (protects from phagocytosis) except Listeria monocytogenes
Which type of meningitis is more common in college-aged students?
Neisseria meningitidis (Meningitis B)
Which meningitis bacterial type can be transferred from mother to fetus?
Listeria monocytogenes
What is a critical symptom of meningitis?
inflammation of the meninges (leading to swelling of the brain [encephalitis] which can then lead to death)
How do viral and bacterial meningitis compare?
Viral is more common but more often is mild
Bacterial is more dangerous/deadly
What organism is responsible for botulism?
Clostridium botulinum
Is botulism caused by the organism itself or a released toxin?
Released exotoxin (neurotoxin)
What type of toxin is botulism caused by? What does this cause?
A type of neurotoxin
Blocks release of acetylcholin
What type of paralysis is caused by botulism?
Causes flaccid paralysis (muscle weakening)
What is the connection with babies, honey, and botulism?
Honey can contain the Clostridium botulinum bacteria that causes infant botulism
Know the major misconceptions about leprosy
- It’s not contagious
- it’s easily curable
-it doesn’t make your limbs fall off - It takes years to develop
what type of organism is associated with leprosy?
Bacteria; Mycobacterium leprae
What is the alternate term for leprosy?
Hansen’s disease
Where does leprosy grow in the human body?
peripheral nervous system (PNS)
How do immune responses contribute to the pathogenesis of leprosy?
the bacteria grow within the peripheral nervous system, when the body’s adaptive immune system begins to attack, it damages the nerves leading to loss of feeling (numbness)
What type of organism causes tetanus?
Bacteria; Clostridium tetani
Is tetanus caused by the organism itself or a released toxin?
Symptoms caused by released neurotoxins
What toxin is released from Clostridium tetani?
Tetanospasmin: released upon death & lysis of
growing bacteria
How does the tetanus toxin affect a person?
Neurotoxin blocks relaxation pathway
- Muscle spasms, lockjaw, opisthotonos
How is polio commonly transmitted to a new host?
Ingested water contaminated with feces
How do most infections with polio affect the host?
Most asymptomatic or exhibit mild symptoms
What is the chance that infection with poliovirus will result in paralysis?
less than 1%
Which body structure is completely paralyzed by a severe polio infection?
Lungs (not able to breathe)
What is the only disease studied in this chapter that is susceptible to
vaccination after the initial exposure?
rabies
Describe hydrophobia
Sight/thought/exposure to water sets off spasms
What type of organism causes rabies?
virus
How is dumb rabies distinct from classical rabies?
Minimal excitability (no foaming of the mouth or biting behavior)
What general type of animal is more likely to show dumb rabies?
cats
What is the vector for arboviral encephalitis?
Mosquitos
How can Zika virus spread person to person?
Sexually
During pregnancy & delivery
Blood transfusions
When is Zika the most severe?
Incidence increase in summer months
What is the etiology of cryptococcosis?
Inhaling contaminated dropping of pigeons
what type of organism can cause meningitis?
bacteria
viruses
fungi
protozoa
what type of organism is Cryptococcus neoformans? where in the body can it effect?
fungus
can effect CNS
True or false
Bacerial meningitis is much more common than viral meningitis and tends to cause a milder form of disease
False
True or false
Botulism is caused by the bacteria and not the toxin
False
What are the misconceptions of Hanses disease?
- It causes limbs to fall off
- ITs highly contagious
- It spread rapidly
- its deadly
