Microbiology - Antimicrobial Agents Flashcards
What class of antimicrobials inhibit cell wall synthesis?
β-lactams:
- Penicillins
- Cephalosporins (1/2/3rd generations)
- Carbapenems
Glycopeptides
What is an example of a penicillin?
Amoxicillin
What is an example of a cephalosporin?
Ceftriazone
What is an example of a Carbapenem?
Meropenem
What is the indication for β-lactam use?
- Gram +ve bacteria
- Gram -ve: 3rd gen cephalosporins + carbapenems
What are some examples of glycopeptides?
- Vancomycin
- Teicoplanin
What are the indications for glycopeptide use?
- MRSA
- C. diff
What class of antimicrobials inhibits protein synthesis?
- Aminoglycosides
- Tetracyclines
- Macrolides
- Chloramphenicol
- Oxazolidinones
What is an example of an aminoglycoside and when is its use indicated?
- Gentamicin
- Gram -ve sepsis
What is an example of a tetracycline and when is its use indicated?
- Doxycycline
- Intracellular (e.g. chlamydia)
What is an example of a macrolide and when is its use indicated?
- Erythromycin
- Gram +ve (penicillin allergy) + Atypical pneumonia
What is an example of chloramphenicol and when is its use indicated?
- Eye drops
- Bacterial conjunctivitis
What is an example of oxazolidinones and when is its use indicated?
- Linezolid
- Gram +ve, MRSA + VRE
What classes of antimicrobial drugs inhibit DNA synthesis?
- Fluroquinolones
- Nitroimidazoles
What is an example of a fluoroquinolone and when is its use indicated?
- Ciprofloxacin
- Gram -ve (e.g. UTI)
What is an example of Nitroimidazoles and when is its use indicated?
- Metronidazole
- Anaerobes + protozoa
What class of drugs inhibits RNA synthesis, give an example and its indications for use?
- Rifamycin
- Rifampicin (never given alone)
- Mycobacteria (e.g. TB)
What classes of antimicrobial drugs target cell membrane toxins?
- Polymyxin
- Cyclic lipopeptide
What is an example of polymyxin and its indications for use?
- Colistin
- Gram -ve
What is an example of cyclic lipopeptide and its indications for use?
- Daptomycin
- Gram +ve, MRSA, VRE
What classes of antimicrobial drugs inhibit folate metabolism?
- Sulfonamides
- Diaminopyrimidines
What is an example of sulfonamides and its indications for use?
- Sulphamethoxazole
- PCP (with trimethoprim = Co-trimoxazole)
What is an example of diaminopyrimidines and its indicated for use?
- Trimethoprim
- UTI
What are some broad spectrum Abx?
- Co-amoxiclav (amoxicillin + claculanic acid)
- Tazocin (piperacillin + tazobactam)
- Ciprofloxacin
- Meropenem
What are some narrow spectrum Abx?
- Flucloxacillin
- Metronidazole
- Gentamicin
What are the four mechanisms of antibiotic resistance and an example of each?
BEAT
- B: Bypass antibiotic-sensitive step in pathway (e.g. MRSA)
- E: Enzyme-mediated drug inactivation (e.g. β-lactamases)
- A: impairment of Accumulation of the drug (e.g. tetracycline resistance)
- T: modification of the drug’s Target in the microbe (quinolone resistance)
What typical organism infects the skin and what Abx is commonly used to treat it?
- S. aureus
- Flucloxacillin
What typical organism causes pharyngitis and what Abx is commonly used to treat it?
- β-haemolytic streptococcus
- Benzylpenicillin
What typical Abx is commonly used to treat mild CAP?
Amoxicillin
What typical Abx’s are commonly used to treat severe CAP?
- Co-Amoxiclav
- Clarithromycin
What typical Abx is commonly used to treat HAP?
- Co-amoxiclav + Gentamicin or Tazocin
What typical organism causes bacterial meningitis and what Abx is commonly used to treat it?
- Meningococcus/Streptococcus
- Ceftriaxone (+Amoxicillin if RFs for listeria)
What typical Abx are commonly used to treat community UTIs?
- Trimethoprim
- Nitrofurantoin
What typical Abx is commonly used to treat nosocomial UTIs?
- Co-amoxiclav
- Cephalexin
What abxs are commonly used to treat severe sepsis?
- Tazocin/ceftriaxone
- Metronidazole +/- Gentamicin
What Abxs are commonly used to treat neutropenic sepsis?
Tazocin + Gentamicin
What Abxs are commonly used to treat Clostridium difficile?
- Metronidazole
2. Vancomycin
