Page 115 - MNU-PM502- Pharmaeutical Microbiology Theoritical Book

Pharm D- Clinical Pharmacy Program Third Level Pharmaceutical Microbiology& Antimicrobials (PM 502)

Streptogramins 50s

Streptomyces spp. naturally secrete pairs of antibiotics from the streptogramin
family that work together to kill other bacteria.
A mixture of Quinupristin/dalfopristin is the only streptogramin available

Mechanism: binds to the 50S subunit of the bacterial ribosome to inhibit protein
synthesis
Dalfopristin: inhibits early stage of protein synthesis

Quinupristin: inhibits the late stage
➢ The combination has bactericidal effect
➢ has activity against aerobic Gram-positive bacteria including

- MRSA G+ve bacteria
- penicillin-resistant S. pneumoniae
- VRE

Toxicity
- pain, inflammation, and thrombophlebitis at
site of infusion

- It is recommended that this drug be given
through a central venous catheter

Oxazolidinones (Linezolid) 50s

completely synthetic compounds
Mechanism: binding the 50S subunit of the bacterial ribosome, it prevents

association of this subunit with the 30S subunit, thus precluding ribosome
assembly.

Bacteriostatic

➢ Linezolid has excellent activity against most aerobic Gram-positive

bacteria, including MRSA, penicillin-resistant S.
pneumoniae, and VRE G+ve bacteria
Drug of last resort

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