Microbial Disorders of the Nervous System - Meningitis to Polio (Week 6) Flashcards
True or False: Meningitis can be bacterial or viral
True
An inflammatory bacterial infection of the meninges (specifically, the two internal ones - the pia and arachnoid mater) that induces meningial swelling, which restricts CSF flow and puts pressure on the organs, causing nausea, pain, vomiting, and reduced brain function
bacterial meningitis
What are some symptoms of bacterial meningitis if the infection is in the spinal cord?
- muscles of neck become stiff
- motor control reduced
What are some symptoms of bacterial meningitis if the infection is in the brain (encephalitis)?
- sensory perceptions are decreased
- behavioural changes
- coma
- death
How do we test for bacterial meningitis?
lumbar puncture (aka “spinal tap”)
Note: this involves extracting CSF
negative (normal) = clear CSF
positive = cloudy CSF
What are some of the regular disease causing bacteria of bacterial meningitis?
- Streptococcus pneumoniae*
- Haemophilus influenzae
- Listeria monocytogenes
- Neisseria meningitidis*
Note: these account for 90% of bacterial meningitis cases
What are some of the opportunistic members of NORMAL MICROBIOTA that can cause bacterial meningitis?
- Staphylococcus aureus
- Streptococcus pyogenes
- Klebsiella pneumoniae
Neisseria meningitidis causes what type of meningitis?
meningicoccal meningitis
What are some of the virulence factors of Neisseria meningitidis?
- fimbriae
- polysaccharide capsules
- lipooligosaccharide (with Lipid A/Endotoxin)
Neisseria meningitidis has a unique characteristic known as ___________
blebbing (bacteria shedding membrane, releasing Lipid A –> causes fever, shock, etc)
What is the leading cause of meningitis?
Streptococcus pneumoniae
What are some of the virulence factors of Streptococcus pneumoniae?
- phosphorylcholine* (main virulence factor; attachment to cells of lungs, meninges, blood vessels; triggers endocytosis)
- capsule
- secretory IgA protease (note: IgA protects mucosal linings)
- pneumolysin (inactivator of lysosomal enzymes)
a gram +ve coccobacillus found in soil, water, and many animals, often obtained through contaminated food/drink
Listeria monocytogenes
True or False: Listeria monocytogenes causes meningitis in immunocompromised individuals, but only a mild flu in healthy adults
True
How does Listeria monocytogenes avoid immune system detection?
by dividing inside macrophages and epithelial cells
(harder to attack them)
Listeria monocytogenes hijacks a cell’s ____________ to help propel it into another cell, so that it never has to leave a cell
actin
Which bacterial causes of meningitis can be inhaled from respiratory droplets?
- Neisseria meningitidis
- H. influenzae
- S. pneumoniae
Which bacterial cause of meningitis can come from unpasteurized milk, cheese, and meat?
Listeria monocytogenes
How does bacterial meningitis spread to the meninges?
Starts from infection of lungs, sinuses, or inner ear
How to prevent meningitis?
- avoid undercooked veggies, unpasteurized milk, undercooked meat, and all soft cheese
- people living in dorms should receive vaccinations
What disease is caused by Mycobacterium leprae?
Hansen’s disease (aka leprosy)
What is the optimal temperature for growth for leprosy?
30 degrees C
Note: therefore the chilly parts of your body (e.g., peripheral nerve endings, earlobes, nose, tips of fingers and toes)
True or False: Signs of leprosy/Hansen’s disease may not be present for 10-30 years, but once the population becomes big enough, the immune system will aggressively attack
True
Note: usually severe at this point and may lead to nerve damage
What disease is caused by Clostridium botulinum toxin?
Note: this is NOT an infection
botulism
Note: the toxin is packaged within an endosphore
