bacterial infections and antibacterial chemotherapy

Question 1

what is the difference between gram positive and gram negative bacteria

Answer 1

negative has a extra part called outer membrane

Question 2

are most bacteria pathogenic

Answer 2

no

Question 3

name drugs that target membrane synthesis

Answer 3

polymyxins, daptomycin

Question 4

name drugs that target nucleotide biosynthesis

Answer 4

sulphonamides, trimethoprim,

Question 5

name the drug that targets RNA transcription

Answer 5

rifamycins

Question 6

name the drug that targets topo isomerase

Answer 6

quinolones

Question 7

name the drugs that target DNA replication

Answer 7

nitrofurans, nitroimidazoles.

Question 8

name drugs that target protein synthesis

Answer 8

amino glycosidases, chloramphenicol, fusidic acid, macrolides, oxazolidinones, streptogramins, tetracyclines, mupirocin

Question 9

name drugs that target cell walls synthesis

Answer 9

beta lactam, bacitracin, cycloserine, ethambutol, ethionamide, Fosfomycin, glycopeptides, isoniazid

Question 10

what is the basis of selective toxicity

Answer 10

1) agent doesn’t get into mammalian cells as easily as they get into bacteria
2) targets processes/structures not in mammalian cells
3) targets processes/structures that are different in mammalian cells
4) pro-drug that is only activated in bacteria

Question 11

what factors influence choice of antibacterial drug for use

Answer 11

1) spectrum activity-narrow spectrum likes less potential for resistance selection
broad spectrum is useful for empiric therapy
2) bacterial or bacteriostatic mode of action
3) potential for selection of resistant bacteria
4) plasma concentration and half life
5) tissue distribution and concentration at site of infection
6) dosing forms
7) potential for adverse side effects and drug interactions

Question 12

what are the three antibacterial susceptibility testing

Answer 12

1) disk diffusion assay
2) etest
3) broth or agar dilution

Question 13

describe the strategy of antibiotic use

Answer 13

1) empiric therapy which is based on predicted likely pathogens and local antimicrobial policies
2) targeted therapy based on predicted susceptibility of infecting organism and local policies.
3) susceptibility guided therapy based on susceptibly testing results.

Question 14

what does pharmacokinetics mean

Answer 14

what the body does to the drug

Question 15

what does pharmacodynamics mean

Answer 15

what the drug does to the bacterium

Question 16

what are some considerations of pharmacokinetics

Answer 16

determination of in vivo efficacy

Question 17

name some key antibiotic/ bacteria combinations

Answer 17

1) flucloxacillin-staphylococcus aureus
2) penicillin- streptococcus pyogenes
3) cephalosporins- gram negative bacilli
4) metronidazole- anaerobes
5) vancomycin- gram positives
6) carbapenems- broad spectrum

Question 18

what is clostridium difficile infection

Answer 18

common cause of antibiotic associated diarrhoea
assumed to be caused by abolition of colonisation resistance.

Question 19

what antibiotics can lead to the above infection

Answer 19

cephalosporins, ciprofloxacin, clindamycin