Lc 12 Flashcards

1
Q

List traits of corynebacterium

A

Gram positive cocci
Non branching
Clumps
Aerobic

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

Is corynebacterium nonmotile and non sporulating?

A

Yes

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

In corynebacterium, humans are the ONLY reservoire. True or false

A

True

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

What is its spreading mechanism?

A

Respiratory droplets, cutaneous lesions, and fomites like desk surfaces

Pharyngeal/ nasal carriage in some convalescent cases

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

Corynebacterium’s virulence factor and its function

A

DT(diphtheria) toxin
—>Classic AB subunit toxin:
B unit: cell binding( R) , translocation(T) —-> toxin delivery via endocytosis
A unit: catalytic (C) ——>pathogenicity/cellular effects in host cells

Elongation factor 2 : stops host cell protein synthesis —> cell dies

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

Is DT encoded on lysogenic bacgeriophage?

A

YES

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

DT regulates production of toxin. Is it chromosomal encoded or phage encoded?

A

Chromosomal encoded

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

If our body is infected, our body will have low ___

A

Iron
—> anytime the organism is making toxin that kills cells, it is upregulating the ability to acquire and utilize iron.

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

Corynebacterium use DT toxin to destroy host cell and acquire iron. True or false?

A

True

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

Local toxic effects of diphtheria

A

Sore throat (pharyngitis)
Cells are destroyed, debris formation,
Form yellow pseudomembrane on your tongue

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

Systemic toxin effects of diphtheria

A

Myocarditis( heart disease) —> pump disfunction, shortness of breath

Soft palate and diaphragm paralysis,

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

Corynebacterium also causes skin infections. How do you diagnose the disease?

A

Isolate from lesions by culture on selective media

Use use tinsdale agar, and dark brown and
Black colony will show up.

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

How do we prevent this disease?

A

Use vaccination(DTaP)
Vaccine is toxoid!

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

What does toxoid do?

A

It inactivates B subunit which then causes A subunit to be not toxic,
So the toxoid blcoks the activity of uptake and activity of toxin but it doesn’t eliminate the ability to colonize or being antigenic. It still cause infection.
But ATTENUATES infection

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

What is the main mechanism of toxoid?

A

When it slows the toxin capabilities of then toxin, we effectively buy time for the host to mount protective immune response and get rid of the bacteria that are producing it.

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

What does corynebacterium jeikeium disease cause?

A

-Skin infection

-bacteremia (blood), endocarditis(heart), pneumonia( lung), osteomyelitis (bone), meningitis (centeal enrvous system)

  • nosocomial infections
17
Q

Listeria monocytpgenes characteristic

A
  • short gram positive rod, catalase positive
  • beta hemolytic , grows at low temp, pH, and High salt

-intestinal colonization

18
Q

What is lysteria’s spreading mechanism?

A

Internalins: InlA ans InlB allow binding and entering to host cells
Listeriolysin O : helps listeria grow in cytoplasm by lysing phagosome (form a pore)
ActA: polar distribution(actin polymerization), —> key for cell to cell spread(helps release to cytoplasm)

19
Q

Lysteria is mainly what kind of disease?

A

Food borne

20
Q

What does the food borne infection do to pregnant women and their fetuses?

A

Vertical transmission,

-early onset: utero

-late onset : during birth. Causes meningitis

21
Q

What kind of people are susceptible to listeria?

A

Elderly,alcoholics,diabetes,corticosteroid users —> those with compromised cellular immnunity

Likely to have meningitis and septicemia(blood poisoning)

22
Q

People with immune competent body have what kind of infections?

A

Gastrointestinal infections, mild flu

23
Q

If you get septices and meningitis, it is very difficult to combat. True or false?

A

True

24
Q

How do you diagnose listeria?

A

Culture of cerebral spinal fluid, blood, amniotic fluid, placenta, fetal tissue

25
Q

Bacillus cereus characteristics

A

Gram positive rod, but when decolorized, it looks like gram negative rod.

-aerobe, beta-hemolytic, motile, spore former
-widely distributed throughout nature

26
Q

What does the spore do?

A

Heat and dessication resistant
Metabolically inactive
Withstands autoclaving
Germinate into cells after decades of persistence

27
Q

Bacillus has enterotoxins. Enterotoxins are harmful to your digestive systems. What are their characteristics?

A

Heat stable toxins- acid tolerant, emetic form like vomiting

Heat labile toxins- diarrheal illness