Overview of Antimicrobials

1
Overview of Antimicrobials

• Dr W.D. Colby
• Microbiology Immunology

2
Classes of Antimicrobials

• ß-lactams
• Aminoglycosides
• Extended macrolide family
• Glycopeptides
• Quinolones
• Tetracyclines
• Miscellaneous

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ß-lactams

• Inhibit cell wall synthesis by blocking
  peptidoglycan cross linking enzymes (PBPs)
• Penicillins
• Cephalosporins
• Cephamycins
• Carbapenems (thienamycins)
• Monobactams

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Penicillins

• Natural
• Aminopenicillins
• Penicillinase-resistant semisynthetic penicillins
• Antipseudomonal penicillins

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Cephalosporins

• 1st generation
• 2nd generation
• 3rd generation
• 4th generation

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Carbapenems

• Very broad spectrum
• ß-lactamase resistant
• Imipenem/cilastatin
• Meropenem

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The Extended Macrolide Family

• Bind to 50 S ribosomal subunit and inhibit
  protein synthesis
• Macrolides
• Azalides (azithromycin)
• Ketolides (telithromycin)
• Oxazolidinones (linezolid)
• Quinupristin/dalfopristin
• Clindamycin

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Tetracyclines

• Bind to 30 S ribosomal subunit and inhibit
  protein synthesis
• Tetracycline
• Doxycycline
• Minocycline

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Aminoglycosides

• Drugs of fear ototoxic, vestibulotoxic,
  nephrotoxic
• Bind to 30 S ribosomal unit
• Gentamicin
• Tobramycin
• Amikacin

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Glycopeptides

• Inhibit synthesis of cell wall phospholipids and
  peptidoglycan polymerization
• Effective against Gram positives
• Vancomycin
• Teichoplanin

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Quinolones

• Bind to DNA gyrase and topoisomerase II
• 1st generation
• 2nd generation
• 3rd generation
• 4th generation

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Evolution of Quinolones
Increasing activity vs Gram ve, atypicals and ana
erobes
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Miscellaneous

• Co-trimoxazole
• Metronidazole
• Fusidic acid