Miscellaneous Antibiotic

Question 1

Polypeptides

Answer 1

Most powerful antibiotics
Very Nephrotoxic
Lack systemic activity following oral administration
Source: Bacillus and Streptomyces spp.

MOA:
Interferes with bacterial cell wall synthesis and most are only effective against G(+) bacteria

Question 2

Teicoplanin

Answer 2

Actinoplanes teichomyetius
Tx of Osteomyelitis and Endocarditis
ADRs: Rash, Hypersensitivity reactions, Neutropenia

Question 3

Polymyxin B

Answer 3

Bacillus polymyxa and Bacillus aeroporous
Useful against G(-) bacteria
Available for ophthalmic, otic and topical use

Question 4

Colistin

Answer 4

Bacillus colistinus
Colistin sulphate – oral use
Colistimethate sodium – parenteral

Question 5

Polymyxin B and Colistin

Answer 5

MOA
1. Surface-active agents
2. Interact strongly with phospholipids and disrupt the structure of cell membranes, resulting to a change in permeability of cell membranes

SoA
Use are restricted to G(-) bacteria
Enterobacter, E. coli, Klebsiella, Salmonella, Pasteurella, Bordetella, and Shigella. Also Pseudomonas
Proteus spp. are intrinsically resistant

Question 6

Mupirocin

Answer 6

Pseudomonas fluorescens
For topical use only
Available as 2% cream or ointment

MOA: Inhibits bacterial protein synthesis by reversible binding and inhibition of isoleucyl transfer-RNA synthetase Bactroban®

SoA For treatment of infections caused by S. aureus or S. pyogenes