Chapter 20 - Microbial Diseases of the Nervous System and Eyes Flashcards
axenic
sterile
ex) CNS, uterus
pathogen entry to CNS
- breaks in bones/meninges
- med procedures
- travel in peripheral neurons to CNS (rabies)
- infect + kill cells of the meninges causing meningitis
Bacterial Meningitis
signs + symptoms
- sudden high fever + severe meningitis inflammation
- encephalitis can result in behavioral changes, coma, death
- develops rapidly
5 species that cause 90% Bacterial Meningitis
1 streptococcus pneumoniae 2 neisseria meningitidis 3 haemophilus influenzae 4 listeria monocytogenes[foodborne]* 5 streptococcus agalactiae
*all are encapsulated + airborne (air droplets)
Top 3 Bacterial Meningitis
1 streptococcus pneumoniae
2 neisseria meningitidis
3 haemophilus influenzae
*streptococcus pneumoniae
-top 3 cause of bacterial meningitis
[G+, diplococci]
*-present in throat of 75% of humans
-meningitis in v young + v old
*neisseria meningitidis
-top 3 cause of bacterial meningitis
[G-, diplococci]
*-epidemic meningitis in college freshman
haemophilus influenzae
-top 3 cause of bacterial meningitis
[G-, pleomorphic rods]
*listeria monocytogenes
-cause bacterial meningitis
[G+, rods]
*-foodborne [uncooked meat/vege, unpasteurized milk]
*streptococcus agalactiae
-cause bacterial meningitis
[G+, cocci]
*-acquired during birth [group B strep]
*-leading cause of meningitis in newborns
meningococca meningitis can become ___demic
EPIDEMIC
bacterial meningitis
diagnosis
- based on symptoms
- culturing of bacteria fr CSF
*bacterial meningitis
treatment + *prevention
T-treated w IV antimicrobial drugs
P*-vaccines available for s.pneumoniae, h. influenzae type B, + n. meningitidis
*-individuals at risk for listeriosis should avoid HIGH RISK FOODS
*3 forms of Botulism
1 Foodborne
2 Infant (most common in USA)
3 Wound botulism
*Botulism
pathogen + virulence factors
Clodstridium botulinum
-different strains produce one of seven neurotoxins
*Botulism
epidemiology
~50 cases of foodborne + wound botulism per year in USA
*infant botulism is most common form in USA
Botulism
treatment + prevention
3 approaches to treatment:
1 washing of intestinal tract to remove clostridium
2 administer antibodies
3 treatment w antimicrobial drugs
-prevented by destroying endospores in contaminated food
*Tetanus vs Botulism
signs + symptoms
tetanus = lockjaw, spasms, + contractions
botulism = flaccid muscles
*Tetanus
pathogen + virulence factors
- Clostridium tetani
* VF-spored grow in deep wound + vegetative cells produce TETANOSPASMIN
*Tetanospasmin
neurotoxin produced by Clostridium tetani spore
-blocks release of inhibitory neurotransmitters at neuromuscular junctions
Polyomyelitis
signs + symptoms,
pathogenesis, transmission
S+S*-90% of cases are asymptomatic infections
T*-by drinking contaminated water
*-has a successful vaccine
*paralytic polio
least common type of polio
-less than 1% are paralytic polio
*Viral Meningitis
diagnosis
diagnosed by characteristics signs +symptoms IN THE ABSENCE OF BACTERIA IN CSF
sudden high fever + severe meningeal inflammation
*similar to bacterial meningitis but no bacteria
*Rabies
pathogenesis
-transmitted via bite or scratch fr infected animal
-virus replicates in muscle cells
+then moves into neurons
+reaches brain via neurons
*Rabies
treatment
1 Human Rabies Immunoglobin [passive immunization]
2 vaccine injections
[active immunication]
3 cleansing infection site
*Rabies
prevention
prevented by controlling rabies in domestic animals
Prion
infectious protein
*Spongiform encephalopathies
- caused by prions
- leaves brain full of holes (sponge)
- -humans contract by EATING MEAT FR INFECTED CATTLE
