Antimicrobials

  1. 1. CELL WALL INHIBITORS
    • Penicillins (beta lactams): amoxicillin, methicillin
    • Cephalosporins: cefoxitin
    • Vancomycin
    • Bacitracin- topical only
  2. 2. PROTEIN SYNTHESIS INHIBITORS:
    • Aminoglycosides - streptomycin, gentamycin (targets ribosomes)
    • Tetracycline- doxycycline, chlorotetracycline
    • Erythromycin
  3. RNA Polymerase
    Rifampcin
  4. MEMBRANE INHIBITOR
    Polymixin B
  5. DAN Replication Inhibitor
    Quinolones- ciprofloxacin
  6. METABOLIC INHIBITORS
    • Sulfa drugs- sulfonamides
    • PABA Inhibitors Trimethoprin- sulfamethoxazole
  7. Mycobacterium Specific
    Isoniazid- prevents waxy layers from forming
  8. ANAEROBIC RESPIRATION INHIBITOR
    Metronidazole
  9. GRAM POSITIVE COCCI
  10. Staphylococcus aureus
    natural flora (nose, skin)
    disease by degrading host tissue, toxin production, inflammation
    LOCALIZED INFECTION: abscesses, boils, impetigo, pimples, food poisoning, scalded skin syndrome

    SYSTEMIC INFECTION: toxic shock syndrome, pneumonia

    VIRULENCE FACTOR: protein A, teichoic acids, many enzymes (coagulase, protease, fibrinolysin), toxins (TSST, alpha toxin, enterotoxin, exfoliatin(sloughs off skin burning appearance))

    • TREATMENT: most broad range antibacterials, quinolones, sulfa drugs,
    • topical cream for skin infections
    • some are b lactam resistant MRSA- use vancomycin or other antibiotics
  11. Staphylococcus epidermis
    • natural skin flora
    • commonly gets on implants such as valves, catheters = colonize
    • coagulase negative
    • glycocalyx for adherence

    SYSTEMIC INFECTION: septicemia and endocarditis

    • TREATMENT: highly resistant to many antibiotics, VANCOMYCIN + RIFAMIPICIN
    • -must remove infected implant
  12. Streptococcus spp.
    • are typed according to:
    • SURFACE CARBS (A-U)
    • HEMOLYSIS (alpha/partial, beta/total and gamma/no)
  13. Streptococcus pyogenes:
    LOCALIZED INFECTION: pharygitis, strep throat, impetigo, boils, abscesses, pimples

    SYSTEMIC INFECTION: septicemia, necrotizing fascitis, SCARLET FEVER

    Complications/post infection disorders: rheumatoid fever, rheumatoid arthritis, glomerulonephritis

    VIRULENCE FACTORS: techoic acid, M proteins, capsule, collegenase, hyaluronidase, hemolysin, toxin (exotoxin A, B and erythrogenic toxin)

    TREATMENT: beta lactams, erythromycin
  14. RHEUMATOID FEVER/ARTHRITIS:
    • autoimmune disorder
    • -antibody to strep M protein cross react with joint and muscle proteins
    • can detect as early as 2 weeks after S.pygenes infection, usually strep throat
    • -symptoms: fever, heart murmur, heart damage, inflammation of heart tissues and joints
    • -can prevent with prompt treatment
    • antibiotic will not help once disorder has developed
  15. ACUTE GLOMERULONEPHRITIS:
    • build up of antibody-antigen complexes in kidney
    • onset about 2-3 weeks after skin infection
    • symptoms subside and patient recovers
    • prvent by treating infections promptly
  16. Enterococcus faecalis (streptococcus faecalis)
    • VRE: vancomycin resistant enterococci
    • -group D beta hemolytic
    • natural flora of gut
    • -associated with hospital acquired UTI by cross contamination with gut microflora on catheters
    • -ENDOCARDITIS after surgery

    TREATMENT: multi-drug resistant NO FAIL SAFE treatments
  17. Veridans Streptococci
    • -flora of oral cavity
    • -alpha hemolytic, no carb groupings
    • mains species: S. mutans, S. sanguis & S. mitus
    • -adheres to tooth enamel via glycocalys
    • -metabolizes sugar in food- lactic acid produced etches tooth enamel
    • plaque: combination of viridans, dextrans and food particles
    • fluoride prevents adherence of strep by coating tooth enamel

    -complication after dental surgery or other breach in gum tissue will allow viridans into blood stream to result in septicemia and endocarditis (infection of heat lining)

    TREATMENT: beta lactams before and after dental surgery
  18. Streptococcus pneumoniae
    VIRULENT FACTOR: capsule (major factor), pneumolysin (cytotoxin)

    LOCALIZED INFECTION: upper respiratory infections, pneumococcal pneumonia, bronchitis

    SYSTEMIC INFECTION: septic shock, pneumococcal meningitis

    TREATMENT: beta lactams (resistant = Vancomycin), erythromycin

    • ~85 different serotypes based on capsular polysaccharides
    • stimulates T cell independent Ab production by passing Ab mediated pathway and triggers B cell directly to produce Ab
    • -alpha hemolytic, no carb grouping
    • most common cause of death due to pneumonia

    • VACCINE: PneumoShot- polyvalent vaccine made up of purified capsular polysaccharides from 25 different serotypes
    • -given upon request for risk groups (health care workers, immunocomp., elderly, booster shot needed every 3-5 yrs
    • new children vaccine now recommended for all children - composed of 7 most common capsular polysaccharides conjugated into a carrier (diphtheria toxoid)
  19. GRAM NEGATIVE COCCI
  20. Neisseria meningitis:
    infection of meninges
    "Epidemic meningitis"
    • symptoms: fever, shock, headache, stiff neck
    • -transmitted by aerosol or direct contact
    • -difficult to diagnose, often asymptomatic at early stage
    • 80% of adults with antibodies to N. meningitis does not have the disease

    VIRULENCE FACTOR: capsule, LPS, IgA protease

    TREATMENT: beta lactams, rifampicin, known resistant to sulfonamides

    • VACCINE: mixture of capsular polysaccharides
    • -given to risk groups
  21. Neisseria gonorrhoeae:
    • sexually transmited disease (STD), direct contact
    • causes gonorhhea, PID (pelivic inflammatory disease) in women, neonatal gonorrheal opthalmia in newborns
    • -symptomatic in men
    • -asymptomatic in female
  22. VIRULENCE FACTOR:
    IgA protease
    Lipooligosaccharides- similar to LPS but has shorter chain
    pili (main virulence factor) - undergoes "ANTIGENIC VARIATION"
    there are multiple silent pilin genes in one genetic locus but one functional promoter - genetic rearragent moves new pili genes to promoter for expression (100s of variation)
    -iron binidng outer membrane proteins
    tolerance of high pH
    • COMPLICATION:
    • PID: pelvic inflammatory disease- bacteria travels from infected cervical tiusse to reproductive tract - result in sterility

    • Newborn conjunctivitis (neonatal gonococcal ophthalmia)
    • -baby contract from mom leads to blindness

    • TREATMENT: beta lactams and cephalosporins
    • neonatal: silver nitrate or erythromycin
Author
Anonymous
ID
47608
Card Set
Antimicrobials
Description
antimicrobials in brief
Updated