Viral and Bacterial Infections Flashcards Preview

Pharmacology > Viral and Bacterial Infections > Flashcards

Flashcards in Viral and Bacterial Infections Deck (43):
0

What is a a) pneumotropic b) lymphotropic c) enterotropic and d) neurotropic infection?

a) One via the lungs: upper and lower respiratory tract epithelial cells
b) lymphatic cells
c) gut epithelial and liver cells
d) neuronal cells

1

What are viruses?

Small infectious agents that can replicate only inside the living called of a host. Depend on a host cells machinery to enter, replicate, and assemble new viruses.

2

What is the term given to a cell in which a virus can enter?

Susceptible cell

3

What do susceptible cells often require?

A specific receptor which can bind a viral attachment protein

4

What are the three types of infections?

Acute, latent or persistent and slow

5

Which (acute, latent or slow) can the immune system contain and clear?

Acute

6

Which (acute, latent or slow) has frequent reactivation?

Latent and slow

7

Which (acute, latent or slow) has the slowest onset of symptoms?

Acute

8

What does HIV stand for?

Human immunodeficiency virus

9

Do a) 10 million, b) 3300 or c) 3.3 million die annually from HIV?

C

10

What does HIV cause?

AIDS- acquired immunodeficiency syndrome

11

What does AIDS target and why?

T helper cells to make them into factories in order to produce thousand of copies of the virus.

12

Why is AIDS so destructive?

Leads to low levels of T helper cells and a loss of cell mediated immunity which highly increases susceptibility to infections

13

How is HIV transmitted?

Unprotected sex, sharing needles, mother to foetus and blood products

14

How many classes of anti-HIV are there today and how to they work?

5 and they target different stages of the viruses life cycle

15

What 5 stages do anti-HIV drugs target?

Entry, integration, transcription, assembly and release/budding.

16

How are anti-HIV drugs takes?

Different classed drugs are combined to act on different points, this is called highly active antiretroviral therapy (HAART)

17

Why is one class of drug not sufficient?

As resistance is common in HIV due to mutations

18

Why are respiratory viruses common?

As the lungs have a very large surface area and come into contact with huge volumes of air every minute.

19

How are respiratory viruses transmitted?

Droplet inhalation, airborne and direct, or exhaled breathe, within close proximity.

20

The deeper you get into the lungs via the respiratory tract the ? Does the infection get?

More severe

21

What does infection cause and how?

General cell destruction, via virus-mediated death and immune mediated death

22

Why is influenza a devil?

Mutates into new strains very easily and frequently

23

What is antigenic shift in viruses?

When 2 virus infect the same cell and a new virus emerges

24

Describe influenzas external morphology?

Polymorphic particles and 3 membrane proteins ( NA, M2 and HA)

25

Describe influenzas interior morphology?

Sheath of matrix beneath membrane and 8 RNA segments encode the viral genes

26

What two steps in influenzas life cycle can be targeted by drugs?

Segment release into the cytoplasm (endoscope release) and general release

27

What drugs are influenza anti viruses?

Neuroamides

28

What two properties do antibiotics have?

To kill (bactericidal) or to inhibit (bacteriostatic)

29

Define the term antibiotics?

A group of drugs that kill or inhibit the growth of pathogens without causing serious damage to the host.

Natural products isolated from bacteria, fungi etc. Semi-synthetic

30

How do bactericidal and bacteriostatic antibiotics work?

Bactericidal disrupt cell wall syntheses and bacteriostatic interfere with DNA/protein synthesis

31

What level of activity do antibiotics have?

Some have very broad and some narrow, a large spectrum

32

How are antibiotics classified?

By mechanism

33

What do sulphonamides or trimethoprim do?

Prevent nucleotide syntheses by inhibiting folate synthesis

34

What do ß-lactams do?

In bacteria and plants they prevent cell wall synthesis

35

What feature do ß-lactam antibiotics have?

A ß-lactam ring

36

What antibiotics inhibit protein syntheses?

Tetracycline (inhibits tRNA binding)
Aminoglycosides (miss read)
Chloroamphenicol (inhibits peptide bond formation)
Pyromycin (causes premature termination)
Enthrythromycin (prevents translocation)

37

What antibiotics inhibit RNA transcription?

Rifamycins

38

How are trimethoprim and sulphonamide given?

Orally. Both absorbed in GI tract

39

What's the difference between a gram negative and a gram positive bacteria?

Gram negative have an outer membrane which creates a peri plastic space, this is not present in gram positive bacteria

40

What is the structure of peptodoglycan?

N-acetyl glucosamine is linked to N-acetyl muramic acid and chains are cross linked by oligopeptides

41

Is it only ß-lactams that prevent cell wall synthesis?

No

42

How do neuroamides work?

Cleaves salicylic acid from HA ok neighbouring viruses, or cleaves salicylic acid from the previously infected cell