Microbiology SGL5

Question 1

Antibiotic

Answer 1

Medicine used to prevent or treat bacterial infection

Question 2

Mechanism that mediate bacterial resistance to drug

Answer 2

• Enzymes that inactivate the drug
• modified target the drug has reduced affect against
• reduce permeability of drug through cell membrane
• export drug using multidrug-resistance pump

Question 3

Most drug resistance is due to

Answer 3

1-genetic change in the organism:
-chromosomal mutation
-acquisition of plasmid or transposon 
2-non genetic changes
E. G. Bacteria within an abscess

Question 4

Chromosome mediated resistance

Answer 4

-Change the target of the drug
-Change the membrane
Chromosomal mutation occur at low frequency and is less of a clinical problem

Question 5

Plasmid mediated resistance

Answer 5

-resistance by encoding enzymes that deactivate the drug
-occurs at higher frequency
R plasmid usually carry the gene
-they’re more clinically important

Question 6

Plasmid mediated resistance

Answer 6

Occurs in many different species, especially gram negative Rod
Frequently mediated resistance to multiple drugs
Have higher rate of transfer from one cell to another usually by conjugation

Question 7

Non genetic resistance

Answer 7

Bacteria inside abscess antibiotic can’t penetrate effectively
Bacteria in resting state
Some strain survive as Protoplast

Question 8

Early generation of cephalosporin

Answer 8

Poor penetration into spinal fluid

Question 9

The minimal inhibitory concentration

Answer 9

The lowest concentration of drug that inhibits the growth of bacteria isolated