Immuno - Microbial Infection Flashcards

1
Q

What are viruses?

A

Not cells in their own right - obligate parasites

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

What do viruses contain as their genetic material?

A

DNA or RNA

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

How do viruses replicate?

A

Using cells nuclear replication machinery

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

What type of specificity do viruses exhibit?

A

Show some host cell specificity however they infect almost all other forms of life.

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

How do viruses divide from one another?

A

Budding from host cells, sometimes allowing the virus to have an outer membrane.
Or cytolysis where a host cell ruptures, therefore releasing virus into the environment.

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

What are the routes of viral infection?

A

Faecal oral
Blood borne
Air borne
Insect vectors

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

What is an example of a virus, its genetic material and its ability to replicate and divide?

A

HIV is an enveloped virus that contains RNA and there reverse transcriptase. HIV allows the host cell to survive after budding.

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

What are bacteria?

A

Prokaryotes

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

What do bacteria lack in terms of cell structure?

A

No organelles or internal membranes

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

What bacteria have internal membranes?

A

Photosynthetic bacteria (not pathogenic)

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

Are prokaryotes haploid or diploid?

A

Haploid

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

What does the haploid number of chromosomes in a bacteria mean in terms of effect?

A

Mutated genes in bacteria will always have an effect.

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

What makes up the cell wall of bacteria?

A

Peptidogylcan

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

How do bacteria divide?

A

Binary fission - very rapidly cells can reach rapid numbers due to exponential division

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

What is the role of the pilli?

A

Important for cell adhesion

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

What is the role of capsule?

A

Prevent cells desiccation and hinder phagocytosis

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

What is the role of the flagella?

A

Aid in motility of the cell

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

How is the shigella bacteria transmitted and were does it affect?

A

Faecal oral route - affects the GI tract.

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

Why does the shigella bacteria have no flagella?

A

Cells has developed a mechanism so that it can nucleate host cell actin filaments at the tail of the bacteria. This then allows the bacteria to be propelled around the cytoplasm and thus infect other cells

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

How do pathogens evolve so quickly?

A

Viruses have no way of correcting mistakes made in DNA replication unlike the polymerases of human cells. This makes viruses much more prone to expressing mutations. Also, bacteria divide at a much faster rate via binary fission and they are haploid, meaning that the rate of expressed mutation occurs a lot more quickly.

21
Q

What are fungi?

A

Single celled eukaryotes

22
Q

What are the 3 groups of fungi?

A

Cutaneous
Mucosal
Systemic

23
Q

How do we classify fungi?

A

Based on where they infect/ cause mycoses which is the term for ideas caused by fungi.

24
Q

What can fungi occur as?

A

Yeasts, filaments or both.

25
Q

What is the difference between yeasts and filaments?

A

Yeasts can bud or divide, filaments (hyphae) have cross walls or septa

26
Q

What is an example of a fungi?

A

Candida Albicans

27
Q

What are protozoa?

A

Single celled eukaryotes

28
Q

What does protozoa include?

A

Intestinal, blood and tissue parasites

29
Q

How do protozoa replicate?

A

Either via binary fission or through the formation of trophozoites

30
Q

What is the life cycle of a protozoa?

A

Complex life cycle involving 2 or more host cells

31
Q

What is the method of infection for protozoa?

A

Usually through an insect or invertebrate vector.

32
Q

What is Genus plasmodium?

A

Causes malaria

33
Q

How is malaria transferred?

A

Mosquito vector

34
Q

How does malaria replicate?

A

Forms mosquito belt and generates trophozoites within the cell which then utilise tissue and blood parasites.

35
Q

What is Leishmania species?

A

Causes leishmaniasis

36
Q

How is leishmaniasis transferred?

A

Sandfly vector

37
Q

How is leishmaniasis replicated?

A

Trophozoites inside cell and utilises blood or tissue parasites

38
Q

What are Helminths?

A

Multicellular metazoa with eukaryotes

39
Q

What are metazoa?

A

Organism that contains differentiated cells and tissues

40
Q

Are helminths microscopic?

A

No - they are often visible to the naked eye.

41
Q

What is the life cycle of helminths?

A

Life cycle occurs outside of the host cell therefore they do not require a vector intermediate.

42
Q

What are the 3 main types of helminth?

A

Roundworms (Ascaris)
Flatworms (Schistosomes)
Tapeworms

43
Q

How do we often treat helminth infection?

A

Chemotherapy however this is not very efficient

44
Q

What are one of the three human disease causing species of flukes?

A

Schistosomes

45
Q

What do schistosomes require?

A

A small intermediate host, such as a freshwater snail

46
Q

When do people get infected with schistosomes?

A

When they enter contaminated water.

47
Q

How does a schistosome infect someone?

A

Cercaria from freshwater snails burrow into the skin of the affected person and migrate to the liver. In the hepatic portal vein, pairs of adult worms release eggs which go back towards the faeces via the gut. However, on their way back, the eggs travel through tissues to cause inflammation as these eggs have spines on them.

48
Q

How do we treat schistosomes?

A

Antimicrobials are available however programmes to remove freshwater snails have also been effective.