Antibiotics - 30S ribosome subunit acting

Question 1

What are the 2 classes of the 30s ribosome subunit acting antibiotics?

Answer 1

Aminoglycosides and tetracyclines.

Question 2

What makes up the aminoglycosides?

Answer 2

Amikacin, gentamicin, and tobramycin.

Question 3

What is the MoA for aminoglycosides?

Answer 3

It gets transported actively into bacterial cells, binding onto the 16s rRNA of the 30s ribosomal subunit.

From there it would cause structural disruption which can cause
1) mRNA misreading leading to protein dysfunction and membrane integrity failure;
2) failure of 70S ribosome assembly.

Active transport is the reason why aminoglycosides aren’t effective for anaerobic bacteria.

Question 4

What are some anaerobic bacteria that are ineffective when given aminoglycosides?

Answer 4

Actinomyces, fusobacterium, clostridium, and bacteroides.

Question 5

Is the aminoglycoside group bacteriocidal?

Answer 5

Yes.

Question 6

What are the tetracyclines?

Answer 6

Doxycycline and tetracycline.

Question 7

What is the MoA of tetracycline entry?

Answer 7

They enter the outer cell wall, in gram negative through aquaporins and in gram positives through active transport channels, they then get transported through the inner cell wall by energy dependent pumps.

Question 8

What differs the MoA of tetracycline and aminoglycosides?

Answer 8

The effect, aminoglycosides produce dysfunctional proteins that disrupts protein production, making it toxic, tetracyclines on the other hand disrupts the aminoacyl-tRNA from entering the ribosome entirely.

Therefore, aminoglycosides are **bacteriocidal **and tetracyclines are bacteriostatic.