Antibiotic Resistance

Question 1

Staph A typcially resistant to which antibiotics

Answer 1

Meticillin

Question 2

Enterococci typically resistant to which antibiotics

Answer 2

Vancomycin/glycopeptide

Question 3

Enterobacteriacae typically resistant to which antibiotics?

Answer 3

Beta lactams (produce beta lactamase)

Question 4

In sensitivity testing, the area around the antibiotics where bacteria cannot grow

Answer 4

Zone of Inhibition

Question 5

Alternative to solid media sensitivity testing that gives a more accurate measurement of MIC

Answer 5

Liquid media- microtitre plate susceptibility testing

Question 6

Which antibiotic cannot travel through gram -ve bacilli?

Answer 6

Vancomycin

Question 7

Uptake of aminoglycosides requires what?

Answer 7

An O2 dependent active transport mechanism

Question 8

Describe the target alteration in MRSA

Answer 8

Altered penicillin binding proteins- bacteria does not bind beta lactams

Question 9

Describe the target alteration in enterococci

Answer 9

Altered protein sequence in gram +ve peptidoglycan

Question 10

Describe the target alteration in gram -ve bacilli

Answer 10

mutations in dihydrofolate reductase gene- resistant to trimethoprim

Question 11

Horizontal transfer of resistance is enabled by what?

Answer 11

Transporons and integrons

Question 12

Process by which bacteria exchange genetic material in horizontal transfer

Answer 12

Conjugation

Question 13

Give 4 examples of acute viral infections

Answer 13

Influenza, measles, mumps, hep A

Question 14

Give 2 examples of latent chronic viral infections

Answer 14

HSV, CMV

Question 15

Give 3 examples of persistant chronic viral infections

Answer 15

HIV, Hep B, Hep C

Question 16

Which viruses have RNA to DNA polymerases

Answer 16

retroviruses (HIV) and help B

Question 17

What was originally developed as an anti-cancer drug and was found to inhibit HIV replication (NRTI)

Answer 17

Azidothmidine (AZT)

Question 18

What are the 2 pyrimidine bases?

Answer 18

CT

Question 19

Give an example of an NRTI which acts as a thymine analogue

Answer 19

Zidovudine

Question 20

Give an example of an NRTI which acts as a cytosine analogue

Answer 20

Lamivudine

Question 21

Give an example of 2 NRTIs that act as purine analogues

Answer 21

Abacovir and Tenofovir

Question 22

Why do some NRTIs act against HBV?

Answer 22

Also contains reverse transcriptase enzyme

Question 23

Which NRTIs are active against HBV?

Answer 23

Lamiduvine, tenofovir

Question 24

How do NNRTIs act?

Answer 24

Bind to different parts of the protein

Question 25

Name the 4 main types of antiretroviral drugs

Answer 25

NRTIs, NNRTIs, Protease Inhibitors and HAART

Question 26

What does HAART aim to do and when does treatment start?

Answer 26

Aims to switch off virus replication. Started when CD4 falls and taken life long.

Question 27

What combination of antiretrovirals are taken in HAART?

Answer 27

2 NRTIs+1NNRTI | 2NRTIs+boosted PI

Question 28

What mutation leads to resistance to lamivudine (pyrimidal NRTI)

Answer 28

M184V

Question 29

What mutation at delta 32 allele lends resistance to HIV

Answer 29

CCR5

Question 30

What is the current treatment for Hep.C

Answer 30

Interferons (naturally occurring antivirals) and ribaflavin