Chapter 22 - Microbial Diseases of the Nervous System Flashcards

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1
Q

What are meninges?

A

-3 continuous membranes: dura mater, arachnoid mater, pia mater

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2
Q

Subarachnoid Space

A

-between pia mater and arachnoid mater
-houses CSF

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3
Q

Blood Brain Barrier

A

-capillary system that prevents the passage of some substances but not others

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4
Q

Drugs cannot cross the BBB unless they are ____ soluable

A

lipid

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5
Q

What is a common lipid-soluable antibiotic?

A

chloramphenicol and sometimes penicillin in large amounds

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6
Q

Meningitis

A

inflammation of the meninges

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7
Q

Encephalitis

A

inflammation of the brain

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8
Q

Meningoencephalitis

A

when both the brain and meninges are inflamed

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9
Q

Initial Meningitis Symptoms

A

-fever
-headache
-stiff neck

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10
Q

Secondary Meningitis Symptoms

A

-nausea
-vomiting

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11
Q

Possible Progressions of Meningitis

A

-convulsions
-coma
-death

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12
Q

The progression of meningitis may only take ___ hours.

A

24

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13
Q

Kernig’s Sign

A

-a diagnostic tool in older or younger patients
-non-invasive
-stiffness when they bend their hamstrings

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14
Q

How is meningitis diagnosed?

A

spinal tap

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15
Q

What is a spinal tap?

A

-collection of a CSF sample from the spinal cord
-needle inserted between L3 and L4

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16
Q

Serology of Meningitis

A

-use a gram stain to diagnose
-keep the sample culture at storage temp and move quickly

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17
Q

What is used to treat bacterial meningitis?

A

3rd generation cephalosporins

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18
Q

*What is not reccomended to treat bacterial meningitis?

A

chloramphenicol due to adverse effects?

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19
Q

Haemophilus Influenzae

A

-aerobic
-gram-negative
-has a capsule
-member of normal throat microbiota
-can cause meningitis when it enters the bloodstream

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20
Q

How many strains of H. influenzae are there? Which most commonly causes disease? Why?

A

-6 strains classified by capsular antigens
-strain B causes 95% of cases

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21
Q

Hib Meningits occurs mostly in _______

A

children under age 4

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22
Q

Is there a vaccine for H. influenzae meningitis

A

Yes: HiB vaccine
-it can be effective by 6 months of age
-is given at 6 weeks of age

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23
Q

Meningococcal Meningitis is cause by which bacteria?

A

Neisseria meningitidis

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24
Q

N. Meningitidis

A

-aerobic
-gram-negative
-diplococcus
-has a capsule
-present in the nose and throat of carriers

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25
Q

How is N. meningitidis spread?

A

-droplet or contact

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26
Q

What are the strains of N. meningitidis? Which is the most common?

A

-strains A, B, C, W135, X, Y
-C is the most common

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27
Q

Who are commonly affected by N. meningitidis?

A

-children under 2
-college students

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28
Q

How long is the progression of N. meningitidis?

A

-it is fast
-may only be 24 hours

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29
Q

What are the primary symptoms of N. meningitidis?

A

throat infection that spreads to the blood stream

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30
Q

What are the secondary symptoms of N. meningitidis?

A

throbbing headache

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31
Q

Is there a vaccine for N. meningitidis?

A

yes

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32
Q

What are possible effects of N. meningitidis?

A

-necrosis that may lead to amputation
-deafness
-paralysis
-death

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33
Q

Petichiae

A

-rash associated with necrosis

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34
Q

Where does Streptococcus pneumoniae commonly reside?

A

-nasopharyngeal region

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35
Q

What % of the population are carriers of S. pneumoniae?

A

70%

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36
Q

Streptococcus pneumoniae

A

-gram-positive
-capsule
-diplococci

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37
Q

What is the leading cause of bacterial meningitis?

A

S. pneumoniae

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38
Q

Who is commonly affected by S. pneumoniae meningitis?

A

children between 1 month and 4 years

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39
Q

What is the mortality rate of S. pneumoniae meningitis in children?

A

8%

40
Q

What is the mortality rate of S. pneumoniae meningitis in elderly?

A

22%

41
Q

How many strains of S. pneumoniae are there?

A

90-92 strains

42
Q

Is there a vaccine for S. pneumoniae?

A

-yes; the most common 20 strains have a vaccine

43
Q

How does S. pneumoniae enter the blood stream?

A

-pneumonia
-otitis media
-surgery/trauma to the head or neck region

44
Q

What is usually used to treat S. pneumoniae?

A

penicillin

45
Q

Listeria monocytogenes

A

-gram-positive
-rod

46
Q

How is L. monocytogenes spread?

A

-food, soil, water
-it is a psychotroph

47
Q

When is L. monocytogenes dangerous?

A

during pregnancy (still born) or in immunocompromised people

48
Q

Listeriosis is the _____ most common cause of bacterial meningitis.

A

fourth

49
Q

What is the infant mortality rate of L. monocytogenes?

A

60%

50
Q

What antibiotic is used for Listeriosis?

A

Penicillin G

51
Q

When can E. coli cause meningitis?

A

in newborns

52
Q

The bacteria that cause meningitis are usually carried by ________.

A

healthy people

53
Q

What is used in prevention of meningitis?

A

-vaccine
-hygiene - not sharing drinks, lip balm, food utensils, etc.

54
Q

Clostridium tetani

A

-obligate anaerobe
-endospores
-gram-positive
-rod

55
Q

Where is C. tetani common?

A

soil contaminated with animal feces

56
Q

What causes the symptoms of tetanus?

A

-A-B exotoxin: tetanospasmin

57
Q

How does tetanospasmin act?

A

-it is released upon lysis of bacteria
-enters CNS via PNS or blood
-no inflammation

58
Q

What does tetanospasmin block at the neuromuscular junction?

A

the relaxation pathway

59
Q

What neurotransmitter does tetanospasmin inhibit?

A

GABA

60
Q

What are the symptoms of Tetanus?

A

-muscle spasms
-lock jaw
-stiff neck
-opisthotonos: bent spine

61
Q

How does Tetanus cause death?

A

-spasms of the muscles in the cardiovascular and respiratory system

62
Q

What is needed for Tetanus to take action?

A

-anaerobic growth conditions ie. improperly cleaned deep wound caused by rusty nails

63
Q

Is there a vaccine for Tetanus?

A

yes: DTaP

64
Q

What type of vaccine is DTaP?

A

-toxoid - inactivated toxin

65
Q

What bacteria causes Botulism?

A

Clostridium botulinum

66
Q

Clostridium botulinum

A

-obligate anaerobe
-endospores
-gram-positive
-rod

67
Q

Where is C. botulism found?

A

soil and many aquatic sediments

68
Q

What does the botulinal A-B exotoxin do?

A

-blocks ACh at the neuromuscular junction

69
Q

What does C. botulinum do?

A

-causes lost muscle tone and leads to flacid paralysis

70
Q

Symptoms of Botulism

A

-abdominal distress
-nausea
-diarrhea or constipation
-blurred/double vision with dilated pupils

71
Q

How long does C. botulinum take to show its full effect?

A

12-36 hours

72
Q

What are the strains of C. botulinum? Which affect humans?

A

-strains A, B, C, D, E, F, G
-humans affected by A, B, E, F

73
Q

Where do humans usually contract C. botulinum?

A

-canned foods (except for tomatoes)
-processed foods

74
Q

Which bacteria causes Leprosy?

A

Mycobacterium leprae

75
Q

What is another name for Leprosy?

A

Hansen’s Disease

76
Q

M. leprae

A

-rods
-acid-fast
-grow optimally at 30℃

77
Q

How does M. leprae act?

A

by invading the PNS

78
Q

How is M. leprae transmitted?

A

by prolonged contact with an infected person

79
Q

Paucibacillary/Tuberculoid/Neural Form of Leprosy

A

-entered by cell mediated immunity

80
Q

What characterizes the paucibacillar form of leprosy?

A

-discoloured skin regions that have lost sensation
-surrounded by a border of nodules

81
Q

Which leprosy is faster to recover from?

A

Paucibacillary (6 months) vs multibacillar (24 months)

82
Q

Multibacillary/progressive Leprosy

A

-cell mediated immunity has failed
-progressive form

83
Q

Multibacilliary Leprosy symptoms?

A

-disfuguring nodules all over the body
-mucous membrane of the nose infected
-lion face
-claw shaped hand
-loss of fingers and toes

84
Q

What is the diagnostic test for leprosy?

A

acid-fast stain or blood test

85
Q

How is leprosy treated?

A

-dapsone (sulfa drug)
-rifampin
-clofazimine
-usually all combined

86
Q

What is clofazimine used for?

A

to minimize antibiotic resistance

87
Q

What causes Polio(myelitis)?

A

poliovirus

88
Q

How is polio transmitted?

A

by ingestion (fecal/oral contamination)

89
Q

What are the initial symptoms of polio?

A

-headache
-sore throat
-fever
-nausea

90
Q

Polio: People with good immunity

A

-transient infection
-show no symptoms

91
Q

How many people are affected with the paralytic form of polio?

A

less than 1%

92
Q

Polio: People with bad immunity

A

-when good immunity fails
-persistent viremia (enters blood)
-virus enters motor neurons
-grows in cell bodies to kill neurons
-leads to paralysis

93
Q

How can polio cause death?

A

paralysis of respiratory muscles

94
Q

Is there a polio vaccine?

A

yes, two actually

95
Q

Salk Vaccine

A

-1955
-inactivated form of all 3 viruses
-IPV inactivated polio vaccine
-needs boosters
-has to be injected

96
Q

Sabin Vaccine

A

-1963
-weakened version of the virus
-OPV oral polio vaccine
-less expensive
-no need for boosters
-1 in a million revert back and cause the actual disease