Antiinfectives I

Question 1

How do we divide antimicrobials?

Answer 1

Antibacterics - against bacteria
Antimycotics - against moulds and yiests
Antivirotics - against viruses

Question 2

Antibacterics according to chemical structure

Answer 2

Antibiotics - products of metabolism of organisms
Chemotherapeutics:
* Sulphonamides
* Chinolones
* Nitrofurans

Question 3

Antibiotics are produced by what, and function how

Answer 3

Bacteria and microscopic fungi
Kill microorganisms or stop their growing

Question 4

Classify antibiotics according to effect on microorganisms

Answer 4

1. Bacteriostatic
2. Bactericidal

Question 5

Bacteriostatic antibiotics

Answer 5

Suppress growth of bacteria
Acute diseases

• Macrolides
• Tetracyclines
• Amfenicols
• Diterpens
• Lincosamides
• Sulphonamides

Question 6

Bactericidal antibiotics

Answer 6

Kill bacteria
Chronic diseases

• Penicillins
• Cephalosporins
• Monobactams
• Carbapenems
• Polyptides
• Glycopeptides
• Ansamycins
• Chinolones

Question 7

Classify antibiotics according to mechanism of action

Answer 7

1. Cell wall synthesis inhibitors: b-lactams, glycopeptides
2. Permeability of cell membrane: polyens, polymyxin, nystatin, amphotericin B
3. Protein synthesis inhibitors: tetracyclines, amphenicols, aminoglycosides, macrolides, pleuromutilins, lincosamides, steroid substances (fusidic acid)
4. Nucleic acid synthesis inhibitors: rifamycins, griseofulvin

Question 8

Classification according to spectrum of action

Answer 8

Narrow-spectrum antibiotic - penicillin G, streptomycin

Broad-spectrum antibiotic - tetracyclines, amfenicols

Slightly-broad spectrum - semi-synthetic penicillins, aminoglycosides, macrolides

Question 9

Anti-staphylococcal antibiotics

Answer 9

macrolides, lincomycin, vancymycin, penicillinase-resistant penicillins, cephalosporins of some generations, rifampin

Question 10

Against G- bacteria

Answer 10

aminoglycosides, polymyxins, cephalosporins, tetracyclines, amphenicols

Question 11

Against yiests and fungi

Answer 11

amphotericin B, nystatin, grizeofulvin, candicidin, natamycin, trichomycin

Question 12

Topical application

Answer 12

bacitracin, neomycin

Question 13

Requirements for an ideal antibiotic

Answer 13

1. Selective target
2. Bactericidal
3. Narrow spectrum
4. High therapeutic index
5. Few adverse reactions
6. Various routes of administration
7. Good adsorption
8. Good distribution to the site of infection
9. Emergence of resistence is slow

Question 14

Name adversal side effects of antibiotics

Answer 14

allergic reaction
emesis
salivation
diarrhea
reduction of vit. B synthesis
development of resistency
difficulties in processing milk fermented products
occurence of residents in meat, animal products

Question 15

Resistance can be

Answer 15

Primary - natural
Secondary - obtained

Question 16

Antibiotics according to chemical structure

Answer 16

1. Penicillins
2. Cefalosporins
3. Tetracyclins
4. Amfenicols
5. Polypeptides and glycopeptids
6. Aminoglycosides
7. Macrolids
8. Lincosamids
9. Ansamycins
10. Diterpens
11. Antibiotics with different structure

Question 17

Beta-lactams are

Answer 17

Penicillins and cefalosporins

Question 18

Testing for effectiveness of antibiotics

Answer 18

1. Diffusion - discs diffusion method (qualitative) or E-test (quantitative
2. Dilution - microdilution and macrodilution

Question 19

Antibiogram is

Answer 19

Qualitative method
Antibiotics discs put on bacterial culture
Measurement of inhibition zone

Question 20

Define MIC (minimum inhibitory concentration)

Answer 20

concentration of drug in blood (or blood plasma) that can affect inhibition of growth and development of microorganisms

Question 21

E-test

Answer 21

Quantitative method
Stripes with concentration gradient
MIC = intersection of the growth inhibition zone and calibrated test strip