GENERAL BACTERIOLOGY

Cards (25)

  • Morphology
    • Spherical (coccus)
    • Rod (bacillus)
    • Comma (vibrio)
    • Corkskrew (spirochete)
    • Spiral (spirila)
  • Spectrum of Activity - arsenal/list of microbes that can be targeted by medicines
  • Sites of Action
    • Cell wall (cidal)
    • Cell membrane (cidal)
    • Nucleic acid: DNA & RNA (cidal); Folate precrusor (static)
    • Ribosomes (static)
  • Source of Antibiotics
    • Cell membrane inhibitors
    1. Daptomycin (Streptomyces roseosporus)
    2. Bacitracin (Bacillus subtilis)
    • Antitubercular agents
    1. Rifampicin (Streptomyces mediterranei)
    2. Cycloserine (Streptomyces orchidaceous)
  • Bactericidal Agents
    • DNA synthesis inhibitor: Fluoroquinolones (FLOXACIN)
    • RNA synthesis
  • Beta-Lactam Antibiotics
    • Ineffective
    1. Cell wall-less microbes
    2. Acid fast bacteria
    3. Intracellular parasites
    4. Resistant microorganisms
    • Adverse reactions
    1. Allergy/anaphylactic (DOC: Erythromycin)
  • Natural Penicillins
    • Penicillin G/Benzylpenicillin
    1. Intramuscular -> acid-labile
    2. DOC for leptospirosis, meningococcus, & syphilis
  • Beta-Lactamase Inhibitors
    • Class I (beta-lactamase only)
    1. Clavam (Clavulanic acid)
    2. Penam (Sulbactam + Tazobactam)
    • Ampicillin + Sulbactam = UNASYN
    • Piperacillin + Tazobactam = PIPTAZ / TAZOCIN
  • Cephalosporins
    • 1st Gen (ceph- & cefa-) [except cefamandole & cefaclor]
    • 2nd Gen (cef- & -lor-)
    • 3rd Gen (cef- + -em/-ine /-one) [except cefapime & cefuroxime]
    • 4th Gen (cef- + -pi- + -me)
    • 5th Gen (-rol-)
  • Carbapenems - wildest spectrum among the beta-lactams
    • Doripenem - wildest spectrum carbapenem
  • Vancomycin
    • MOA: binds to D-alanyl-D-alanine portion → blockade of transpeptidation
    • USES: DOC (drug of choice) for MRSA (methicillin-resistant Staphylococcus aureus) & MRSE (Methicillin-resistant Staphylococcus epidermidis) 2nd line treatment for pseudomembranous colitis
    • A/E: red man syndrome - Tx: Diphenhydramine + Discontinue (temporarily)
  • Tetracyclines (Broadest-Spectrum antibiotic)
    • USES: DOC for relapsing fever, lymphogranuloma venereum, psittacosis, rickettsia infection
    • DOXYCYCLINE; prophylaxis of leptospirosis; DOC for Lyme disease
    • MINOCYCLINE; most potent
  • Aminoglycosides
    • STREPTOMYCIN = DOC for zoonotic infections
    • Brucellosis / undulant fever
    • Bubonic plague
    • Tularemia / rabbit fever
  • Aminoglycosides (A/E)
    • VESTIBULOTOXICITY
    • Streptomycin & Gentamicin
    • OTOTOXICITY
    • Neomycin, Amikacin, & Kanamycin
    • NEPHROTOXICITY
    • Neomycin, Tobramycin, & Gentamicin
  • CHLORAMPHENICOL
    • USES: former DOC for typhoid fever (current DOC: ceftriaxone)
  • LINCOSAMIDES
    • MOA: resemble macrolides in receptor site, mode of action, and spectrum of activity
    • A/E: overuse of clindamycin → overgrowth of clostridium difficile bacteria → pseudomembranous colitis
  • OXAZOLIDINONES
    • A/E: reversible thrombocytopenia
  • MACROLIDES
    • ERYTHROMYCIN: DOC for diphtheria & pertussis
    • A/E: AZITHROMYCIN – ARRHYTHMIAS
  • FLUOROQUINOLONES
    • CIPROFLOXACIN: 1st line agent for anthrax
    • CIPROFLOXACIN & LEVOFLOXACIN: UTI
  • ANTIMETABOLITE COMBINATIONS
    • SULFAMETHOXAZOLE + TRIMETHOPRIM (COTRIMOXAZOLE) DOC for Pneumocystis carinii pneumonia in AIDS patients
  • RIFAMPICIN
    • MOA: inhibits RNA polymerase → inhibits RNA synthesis
  • DAPSONE
    • USE: TX of leprosy (with rifampicin)
  • NITROIMIDAZOLE (METRONIDAZOLE, TINIDAZOLE)
    • MOA: inhibits protein synthesis, and causes DNA strand breakage
  • METRONIDAZOLE
    • TRICHOMONAS VAGINALIS (TRICHOMONIASIS)
    • ANAEROBES: BACTEROIDES FRAGILIS (intestinal abscess) & CLOSTRIDIUM DIFFICILE (pseudomembranous colitis)
  • URINARY ANTISEPTICS
    • FOSFOMYCIN
    • METHENAMINE: acidify the urine and liberate formaldehyde
    • NALIDIXIC ACID
    • NITROFURANTOIN