Microbiology 2 -Stop the Prokaryotes (Targets for Antibiotic Chemotherapy)

Question 1

Describe the basis of Antibacterial Chemotherapy

Answer 1

• To treat the bacterial infection with drugs which are toxic to bacteria whilst ensuring minimal toxicity to the host

Question 2

What is meant by the term Bactericidal (Antibiotic) ?

Answer 2

Antibiotic that kills bacteria

Question 3

What is meant by the term Bacteriostatic (Antibiotic) ?

Answer 3

Antibiotic that stops bacteria from growing

Question 4

What is meant by Minimum Bacterial Concentration (MBC) ?

Answer 4

The lowest concentration of antibacterial agent required to reduce the viability of a bacterial inoculum by >_ 99.9%

Question 5

What is meant by Minimum Inhibitory Concentration (MIC) ?

Answer 5

The lowest concentration of a chemical which prevents visible growth of bacterium

Question 6

When is a drug considered to be Bactericidal ?

Answer 6

When the MBC is no more than 4x the MIC

Question 7

A drug is Bactericidal when the MBC is no more than 4x the MIC. TRUE or FALSE

Answer 7

TRUE

Question 8

State the 2 target strategies of Antibacterial Chemotherpay

Answer 8

1) Targeting reactions

2) Targeting structures

Question 9

Anabolic Cell Metabolism is a strategy to target reactions. TRUE or FALSE

Answer 9

TRUE

Question 10

Anabolic cell metabolism consists of 4 class reactions. TRUE or FALSE. If false, correct the statement.

Answer 10

False. It consists of 3 reactions; Class 1, 2 and 3.

Question 11

During Class 1 reactions, carbon sources are used to produce simple compounds. TRUE or FALSE

Answer 11

TRUE

Question 12

Class 2 reactions use Class 1 products to make small molecules. TRUE or FALSE

Answer 12

TRUE

Question 13

Class 3 reactions use Class 2 products to make larger molecules. TRUE or FALSE

Answer 13

TRUE

Question 14

Class 2 reactions can be used to inhibit synthesis of essential metabolites. e.g: Folate Synthesis. TRUE or FALSE

Answer 14

TRUE

Question 15

Name 2 classes of drugs involved in inhibition of Folate synthesis

Answer 15

1) Sulfonamides

2) Trimethoprim

Question 16

Class 3 reactions can be used to inhibit synthesis of Cell wall, Protein and Nucleic acid. TRUE or FALSE

Answer 16

TRUE

Question 17

Give examples of drugs involved in inhibition of Cell wall synthesis

Answer 17

1) Cycloserine
2) Vancomysin
3) Bacitracin
4) B-Lactams (e.g: Penicillin, Cephalosporins)

Question 18

Give examples of drugs involved in inhibition of Protein synthesis

Answer 18

1) Tetracylines
2) Aminoglycosides
3) Chloramphenol macrolides
4) Erythromycin

Question 19

Give examples of drugs involved in inhibition of Nucleic acid synthesis

Answer 19

1) Quinolones

2) Rifampicin (+related compounds)