microbial disorders of the nervous system (wk 6) Flashcards
(42 cards)
what is bacterial meningitis
–> which part of the meninges
inflammatory infections of the meninges
(particularly the two internal ones, the pia and arachnoid mater)
what does bacteria in the menginges symptoms
Induces meningial swelling, restricting CSF flow and putting pressure on the organs, causing nausea, pain, vomiting, reduced brain function
if bacteria meningitis is in the spinal cord what can happen
muscles of the neck will become stiff and motor control will be reduced
what happens in encephalitis;; bacterial menignitis that effects the brain
sensory perceptions are decreased, behavioural changes occur, and coma or death may result
what is the test for bacterial meningitis
what is a positive and negative test
lumbar puncutre/ spinal tap
positive test= cloudy CSF
negatie test= clear CSF
which opportunistic members of normal microbiota
Staphylococcus aureus
Steptococcus pyogenes
Klebsiella pneumoniae
what regular disease causing bacteria can cause bacterial memingisti (90%of cases)
Streptococcus pneumoniae
Haemophilus influenzae
Listeria monocytogenes
Neisseria meningitidis
what does neisseria meningitidis cause?
meningococcal meningitis
what are nesirreria meningitidis virulence factors?
fimbriae and polysaccharide capsules, Lipooligosaccharide (with Lipid A/Endotoxin), and various factors to prevent digestion in phagocytes
what mechanism does neisseria meningitidis work through?
blebbing –> it releases endotoxin without dying
what is the leading cause of meningitis
streptococcus pneuomniae
what are streptococcus pneumonia virulence factors?
what is the primary virulent factor?
capsule, secretory IgA protease, pneumolysin (inactivator of lysosomal enzymes)
phosporylcholine (attachment to cells of lungs, meninges, blood vessels – and triggers endocytosis)
in which type of people can listeria monocytogenes cause meningitis in?
Causes meningitis in immunocompromised individuals, but only mild flu in healthy adults.
how can you get listeria monocytogenes
contaminated food/drink
what is listeria monocytogenes
Gram +ve coccobacillus found in soil, water, and many animals (no endospores)
Avoids immune system detection by dividing inside macrophages and epithelial cells
how does listeria monocytogenes work
gets phagocytose and divides and then hijacks actin cytoskeleton to move –> creates a false pseudopod that allows it to go into another cell and infect in by an endosome
Streptococcus pneumoniae
Haemophilus influenzae
Listeria monocytogenes
Neisseria meningitidis
how do you get all these bacteria
and how do they spread
N. meningitidis, H. influenzae, S. pneumoniae – inhaled in respiratory droplets
Listeria – unpasteurized milk, cheese, meat
Bacteria usually spreads to meninges from infections of lungs,
sinuses, or inner ear
Head or neck trauma may expose meninges directly
Bacteria ferment glucose in CSF for energy
how to prevent bacterial meningitis
Susceptible individuals should avoid undercooked veggies, unpasteurized milk, undercooked meat and all soft cheese
People living in dormitories should receive vaccinations
what is the causative agent of Hansens disease (leprosy)
mycobacterium leprae
Signs of disease may not be present for 10-30 years, but when the population becomes big enough, your immune system will aggressively attack them
what is the optimal growth for mycobacterium leprae
Optimal growth – 30°C – so in the chilly parts of your body (peripheral nerve endings, earlobes, nose, tips of fingers and toes.
causative agent of botulism?
clostridium botulinum toxin
NOT AN INFECTION; just the toxin
what are the 2 types of botulism
food borne, infant and wound
Foodborne/Wound Botulism symptoms: paralysis of all voluntary muscles, blurred vision, nausea (death from respiratory paralysis
Infant botulism: not ingested, but C. botulinum can infect GI tract due to absence of microbiota
how does the botulism toxin act at the neuromuscular junction?
botulism blocks the release of acetylcholine at a neuromuscular junction –> no muscle contraction (relaxed)
tetanus causative agent
clostridium tetani
