Antimicrobials

Question 1

What are the four quadrants for the antimicrobial spectrum?

Answer 1

Gram positive aerobes - Gram negative aerobes - Obligate anaerobes - Penicillinase producing Staph

Question 2

Are there bacteria which don’t fit into the four quadrant spectrum? What are they called?

Answer 2

Yes - Atypical bacterial species

Question 3

Give an example of some Atypical bacteria

Answer 3

Rickettsia - Mycoplasma - Chlamydia - Borrelia - Bartonella - Mycobacterium

Question 4

Outline a responsible way to use antimicrobials

Answer 4

Think Global - Act Local

Question 5

When should antibacterials be used?

Answer 5

Definite diagnosis - Likely diagnosis when everything taken into account - Disease will progress without medical intervention - If animal in critical condition

Question 6

What clues can tell you if it is a bacterial infection or not?

Answer 6

Heat, redness or swelling?
Pyrexia?
Neutrophillia?

Question 7

What three cases especially are very unlikely to be a bacterial infection?

Answer 7

Vomiting without diarrhoea - Haematuria in cat <10 - Blood in faeces

Question 8

What are the most likely bacterial infections of the mouth?

Answer 8

Gram negative and anaerobic from GIT

Question 9

What are the most likely bacterial infections of the respiratory system?

Answer 9

In bronchi - bordatella

Pneumonia - could be anything

Question 10

What are the most likely bacterial infections of the skin?

Answer 10

Staphlococcus

Question 11

What are the most likely bacterial infections of the urinary tract?

Answer 11

Gram negative from urethra - Possibly Staph

Question 12

What are the most likely bacterial infections of the liver?

Answer 12

Gram negative from bile duct

Question 13

What are the most likely bacterial infections of cat wounds?

Answer 13

Mycobacterium

Question 14

In general, if bacteria are not ______ to a drug in vitro they will be resistant __ ____

Answer 14

Susceptible - In vivo

Question 15

What does MIC stand for? What does it mean?

Answer 15

Minimum inhibitory concentration - Lowest concentration of drug that will inhibit bacterial growth

Question 16

What is usually used to determine therapeutic dose?

Answer 16

MIC90

Question 17

What antimicrobials inhibit cell wall synthesis?

Answer 17

Penecillin - Cephalosporins - Bacitracin

Question 18

What antimicrobials inhibit cell membrane function?

Answer 18

Polymyxins - Amphotercin - Imidazoles - Nystatin

Question 19

What antimicrobials inhibit protein synthesis in the nucleus?

Answer 19

Chloramphenicol - Macrolides - Lincosamides

Question 20

What antimicrobials inhibit protein synthesis?

Answer 20

Tetracyclines - Aminoglycosides

Question 21

What antimicrobials inhibit nucleic acid synthesis?

Answer 21

Sulphonamides - Trimethoprim - Quinolones - Metronidazole - Rifampin

Question 22

What does Bacteriostatic and Bactericidal mean?

Answer 22

Bacteriostatic = inhibits growth of organisms
Bactericidal = kills bacteria

Question 23

For bacteriostatic drugs to be effective they have to be maintained at what level and for how long?

Answer 23

Over 80% of MIC - at least 50% of 24hrs

Question 24

Give examples of Bacteriostatic drugs?

Answer 24

Chloramphenicol - Lincosamides - Macrolides - Tetracyclines - Non-potentiated Sulphonamides

Question 25

Give examples of Bactericidal drugs?

Answer 25

Penicillins - Cephlasporins - Aminoglycosides - Fluoroquinolones - Potentiated Sulphonamides (TMPS) - Metronidazole

Question 26

What are the two types of bactericides?

Answer 26

Concentration dependent - Time dependent

Question 27

What level do concentration dependent bactericides have to stay at to be?

Answer 27

Eight times the MIC

Question 28

What determines the therapeutic effect of concentration dependent bactericides?

Answer 28

The area under the concentration curve

Question 29

Why can't bacteriostatic drugs not be used in conjunction with time dependent bactericidal drugs?

Answer 29

Bacteria need to be multiplying for time dependent bactericidal to work

Question 30

Which drugs are ineffective against gram positive aerobes?

Answer 30

Aminoglycosides - Metronidazole

Question 31

Which drugs are ineffective against gram negative aerobes?

Answer 31

Metronidazole - Penicillin G - Lincosamides/Macrolides

Question 32

Which drugs are ineffective against obligate anaerobes?

Answer 32

Fluroquinolones - Aminoglycosides

Question 33

Which drugs are ineffective against Penicillinase producing Staphlococcus?

Answer 33

Penicillin G - Aminopenicillins - Metronidazole

Question 34

What bacteria is Penicillin effective against?

Answer 34

Gram positive aerobes and Obligate anaerobes

Question 35

What is a 'brown' drug? Give an example of an all quadrant brown drug

Answer 35

Drugs that have a moderate effect on bacteria - TMPS

Question 36

Which drug has a brown effect for most of the quadrants but is excellent against atypical bacteria?

Answer 36

Tetracyclines

Question 37

Which areas of the body are quite hard for antimicrobial drugs to access?

Answer 37

Brain - Eye - Prostate - Bronchus - Mammary glands

Question 38

Which drugs have poor penetration of hard to reach tissues?

Answer 38

Penicillins - Cephalosporins - Beta lactamase inhibitors - Polymixins - Aminoglycosides

Question 39

Which drugs have good penetration of hard to reach tissues?

Answer 39

Sulphonamides - Trimethoprim - Lincosamides - Macrolides - Tetracycline

Question 40

Which drugs have a great penetration of difficult to reach tissues?

Answer 40

Chloramphenicol - Fluoroquinolones - Lipophillic tetracyclines - Metronidazole - Rifampin

Question 41

When would surgical prophylaxis be acceptable?

Answer 41

High risk of infection either because of long surgery, use of implants, patient health and the disease process

Question 42

When should surgical prophylaxis be administered?

Answer 42

Before the surgery

Question 43

What is a useless surgical prophylactic? Why?

Answer 43

Long acting amoxycilin - takes 12 hours to reach therapeutic concentration

Question 44

Which bacterial quadrants is fluoroquinolones good and bad at?

Answer 44

Green - Gram negative aerobes, Staph Brown - Gram positive aerobes Red - Obligate anaerobes

Question 45

Which drugs are effective against gram positive aerobes?

Answer 45

Penicillin - Cephalosporins - Lincosamides - Tetracyclines - Rifampin - Fluoroquinolones

Question 46

Which drugs are effective against gram negative aerobes?

Answer 46

Fluoroquinolones - Aminoglycosides - Cephalosporins - Amoxy-clav

Question 47

Which drugs are effective against Staph?

Answer 47

Amoxy-clav - Cephalosprins - Cloxacillin - Fluoroquinolones - Rifampin - Clindamycin (not great)

Question 48

Which drugs are effective against Obligate anaerobes?

Answer 48

Penicillin - Amoxy-clav - Clindamycin - Metronidazole - Cloramphenicol - Rifampin