Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

USC Microbiology 1 > Week 11 Diseases of nervous system > Flashcards

Week 11 Diseases of nervous system Flashcards

(62 cards)

Start Studying
1
Q

Meninges

A

Three layers: dura mater (in contact with skull), arachnoid mater, pia mater (in contact with blood vessel and brain)
Surrounds brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Nervous system divisions

A

CNS: brain and spinal cord
PNS: nerves (communication between brain and rest of body)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Bacterial meningitis causes (3) and characteristics

A

Streptococcus pneumoniae, haemophilus influenza, neisseria meningitidis
All have capsule (protection from phagocytosis)
Enter CSF, then die rapidly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Bacterial meningitis symptoms (5)

A

Fever, headache, stiff neck, nausea, vomiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Other causes of bacterial meningitis (3)

A

Listeria monocytogenes
Streptococci group B
Staphylococci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Haemophilus influenza characteristics

A

Aerobic, gram negative, normal throat flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

H. influenza diseases

A

bacterial meningitis, epiglottitis, otitis media, pneumonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

WHat about h. influenza contributes to pathogenicity

A

Capsular carbohydrate antigen type B (Hib)
Vaccine is based on this antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Neisseriaceae characteristics

A

Non spore forming diplococci, aerobic or facultative, gram negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pathogenic species of neisseriaceae and location

A

N. gonorrhoea and N. meningitidis
Found on human mucosal membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

N. meningitidis medium

A

Chocolate agar (brown)- contains red blood cells which are heated and killed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

N. meningitidis disease

A

meningococcal meningitidis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

N. meningitidis serotypes

A

A (widespread epidemic, africa)
C (North america and other parts of world)
VAccine based on capsular polysaccharide for serotypes A and C
No vaccine for B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

N. meningitidis treatment

A

doxycycline, ofloxacin, erythromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Meningitis signs and symptoms

A

Appearance of neutrophils and N. meningitidis in CSF smear
Can proliferate in blood leading to sepsis, then enters into nervous system (meninges)
Spreading rash on trunk, arms and legs, form crusty vesicles on skin surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

S. pneumoniae disease

A

streptococcal meningitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

S. pneumoniae location , vaccine, treatment

A

Nasopharyngeal region, vaccine against capsular antigen, penicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Clostridium characteristics

A

Obligate anaerobe (lacks cytochromes needed to use O2 as terminal hydrogen acceptor)
Catalase and peroxidase negative
Gram positive
Spore forming (when nutrients insufficient)
Ferments carbohydrates
Encapsulated alpha and theta/gamma? haemolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Clostridium species (4) and diseases

A

Perfringens: gas gangrene and food poisoning
Difficile: toxic enterocolitis (antibiotic associated pseudomembrane colitis)
Tetani (spores): tetanus
Botulinum: botulism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

C. tetani

A

Obligate anaerobe, common in soil, produces spores
Potent neurotoxin (tetanospasmin) released when lysed or killed
Non communicable as does not spread from infectious site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Tetanospasmin MOA

A

Blocks relaxation pathways in muscles: they contract but cannot relax leading to paralysis and pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

C. botulinum

A

Spore forming, anaerobe
Produces potent exotoxin under anaerobic conditions
Serological types A-E (5)
Infant botulism can occur due to competition with normal flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Botulinum exotoxin characteristics

A

Toxin not formed in acidic food eg tomatoes
Toxin destroyed with cooking heat
Type A spore most resistant to heat
Antibiotics not effective against toxin, instead neutralised with antitoxins A-E from mice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Leprosy cause

A

Mycobacterium leprae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Mycobacterium leprae characteristics
Acid fast, related to M. tuberculosis Optimal growth temperature 30 degrees Long generation time Cannot be cultured outside body (armadillos used as lower body temp than humans) Grows in PNS and on skin
26
Forms of leprosy (2)
Tuberculoid (neural): regions of skin lose sensation, surrounded by borders of nodules Lepromatous (progressive): skin cells infected, disfiguring nodules form all over body
27
Tuberculoid leprosy- who it occurs in, diagnosis
In ppl with good immune system Detection of acid fast bacteria in fluid from slit cut in cool site eg earlobe Lepromin test: extract from advanced form injected into skin yields visible reactive, this test is negative in later stages of the disease
28
Lepromatous leprosy characteristics (5)
Occurs in people without effective cell mediated immunity Mucous membrane of nose and face most affected Clawed hands Not very contagious, requires prolonged intimate contact COmplications may occur but usually does not cause death
29
Viral diseases of nervous system (3)
Poliomyelitis Rabies Arbovirus encephalitis (eastern equine, western equine, st louise, california, japanese B, yellow fever, Powassan virus, dengue fever, colorado tick borne encephalitis) Usually result in death
30
Poliomyelitis progression
Infection initiated by ingestion of virus Multiplies in throat and small intestine, invades tonsils and lymph nodes in neck and ileum Enters blood (viraemia), then central nervous system Multiplies in cytoplasm of motor nerves and kills them resulting in paralysis
31
Polio diagnosis and prevention
Isolation of virus from faeces and throat, cell culture Vaccines: salk (inactivated with formaldehyde), sabine (live attenuated) Iron lungs mechanically respirate paralysed lungs
32
Rabies
Caused by rabies virus (rhabdovirus, bullet shape) Always results in fatal encephalitis if untreated by vaccination Human acquires from infected animal Long incubation period enough to allow immunity to develop from post exposure vaccination
33
Rabies progression
Virus within peripheral nerves not accessible to immune system until cells of CNS destroyed Agitation period: breakdown of NS cells Calm period: virus multiplying within NS
34
Rabies symptoms
Spasms of mouth muscles and pharynx, hydrophobia, total destruction of CNS cells and death
35
Furious rabies
Animal restless, highly excitable, snap at anything within reach eg dog
36
Paralytic rabies
Animal not excited, relatively quiet, might snap if irritated eg cat
37
Rabies diagnosis
Presence of viral antigen in saliva, serum or CSF using immunofluorescence technique
38
Rabies treatment
Anti-rabies vaccine and immunoglobulins post exposure (prophylaxis) Treatment for any unprovoked bite from animal not available for examination
39
Rabies vaccination (3)
Old (pasteur): attenuated, dried spinal cord of rabies infected rabbit Human diploid cell vaccine (5-6 injections over 28 days) Passive immunisation: human immunoglobulin
40
Arbovirus disease
Arboviral encephalitis
41
Arbovirus naming
Initial location of isolation and diseases they produce Categorised based on morphology, biochemistry and antigenic similarities
42
Rabies carriers
Skunk, fox, bat, bobcat, raccoon, dog, cat
43
Arbovirus general characteristics
Enveloped virions with single stranded RNA Envelope contains haemagglutinin and lipoproteins (so can be inactivated by lipid solvents) Found in blood and tissues, but not stool Diagnosed using serological techniques
44
What differentiates reoviridiae from other arboviruses
Reoviridiae are double stranded RNA viruses without envelopes
45
Reservoir and transmission of arboviruses
Infection transmitted from arthropods to susceptible vertebrate host
46
Invertebrate vectors of arboviruses (5)
Aedes mosquito, wood tick, tick , anopheles mosquito, flea
47
Survival of arbovirus between seasons (2)- needed as arthropods are not present in all seasons
Infected adult arthropods hibernate between seasons to survive Transovarian transmission: infected female arthropod transmits virus to progeny
48
Mechanism of arboviruses
1. Infection of vertebrate by a biting arthropod 2. Virus amplifies in reticuloendothelial system 3. Virus become localised in various target organs causing cell necrosis, and inflammation which leads to fever 4. Transmission along neural pathway 5. Enters CNS causing meningeal inflammation of neuronal dysfunction encephalitis
49
Yellow fever progression
Liver and hepatic cell necrosis Haemorrhage due to failure of liver to produce clotting factor
50
Dengue haemorrhagic fever
Fever associated with rash and flu symptoms Changes in small dermal blood vessels: increased vascular permeability and infiltration of mononuclear cells
51
Arbovirus treatment
None other than supportive care
52
Arbovirus prevention
Avoiding contact with infected arthropods, elimination of arthropod bleeding sites, use of insecticides
53
Arbovirus vaccination
Immunisation of horses and humans against west and east equine encephalitis
54
Cryptococcus neoformans characteristics
Fungal meningitis Yeast like with spherical cell Polysaccharide capsule Mainly in soil contaminated with pigeon droppings
55
Cryptococcus neoformans transmission
Inhalation -> lung infection -> blood -> meninges
56
Cryptococcus neoformans identification
serology detecting antigen in CSF and blood
57
Trypanosoma gambiense and T rhodesiense
Cause african trypanosomiasis (sleeping sickness) Protozoan parasites Trypanosoma multiplies in Tsetse fly saliva, transmitted to human through bite Bite -> blood stream -> spleen lymph nodes and liver
58
Trypanosoma symptoms
Invasion of CNS results in reduced concentration, ability to talk and walk Extreme tiredness -> continual sleeping -> coma -> death
59
Trypanosoma reservoir
Game animals, cattle and sheep, common in Africa
60
Bovine spongiform encephalopathy (BSE)
Caused by prion Mad cow disease (in cows), Creutzfeldt-Jakob disease in humans from transplanted nerve tissue, contaminated surgical instruments or meat from infected cows Cause neurological damage
61
How do prions cause neurological damage
induce abnormal folding of specific normal cellular proteins in the brain from alpha protein (normal) to beta sheet (abnormal)
62
Prion classification
Nonliving, infectious proteins

USC Microbiology 1 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions