Chapter 22 Microbial diseases of nervous system Flashcards
What are the three layers of the brain membranes?
- Dura mater (outermost)
- Arachnoid matter (middle contains subarachnoid space w/cerebral spinal fluid)
- Pia mater: inner membrane
What are the common routes of CNS invasion of bacteria?
Blood stream and lymphatic vessels
What is meningitis?
Inflammation of the meninges
What is encephalitis?
Inflammation of the brain
What is a major symptom of encephalitis and meningitis? Major difference of symptom?
Similar in both: Headache
Specific to encephalitis: more seizures/ cranial nerve palsies
Specific to meningitis: neck stiffness/ photophobia
What are the four bacteria that commonly cause meningitis?
Streptococcus pneumoniae
Neisseria meningitides
Haemophilus influenza type B (Hib)
Listeria monocytogenes
What are some of the characteristics that the different meningitis 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 meningitides
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
What type of toxin is botulism caused by? What does this cause?
A type of neurotoxin
Blocks release of acetylcholine
What type of paralysis is caused by botulism?
Flaccid paralysis (muscle weakening)
What is the connection with babies, honey, and botulism?
Bees carry Clostridium botulinum on their bodies, so it is also found in the honey they produce. Babies don’t have a built enough immune system like adults do, so when ingested, the bacteria can take over, produce toxins and cause botulism in babies
what type of organism is associated with leprosy?
Bacteria; Mycobacterium leprae
Know the major misconceptions about leprosy.
Leprosy is thought to be flesh-eating disease; however, it is actually the fact that it really causes loss of feeling in extremities that allows for injuries or secondary infections to occur, leading to need for amputations.
Because of the misguided stigma that leprosy leaves a disfigured appearance, and is super contagious, people with the disease are often ostracized.
It is not deadly; 95% of the population is immune to disease and there are viable treatments
What is the alternate term for leprosy?
Hansen’s disease