IC7

Cards (27)

  • Microorganisms can be categorized as acellular or cellular, including viruses, prions, prokaryotes, and eukaryotes
  • Types of bacteria based on morphology, Gram staining, acid-fast staining, and oxygen requirements
  • Atypical bacteria such as Rickettsia, Chlamydia, and Mycoplasma
  • Endospores and fungi, including Zygomycetes, Ascomycetes, Deuteromycetes, and Basidomycetes
  • Antimicrobial resistance (AMR) is a global threat
  • Significance of antimicrobial susceptibility testing (AST) parameters for antimicrobial drug effectiveness
  • Antimicrobial susceptibility testing (AST) parameters
    • Minimum inhibitory concentration (MIC)
    • Spectrum of activity
  • Minimum inhibitory concentration (MIC)
    • Lowest concentration of a drug that prevents visible growth of a bacteria or fungi
    • Determines the effectiveness of antimicrobial drugs against specific microorganisms
  • Narrow spectrum antimicrobial
    • Targets only specific subsets of pathogenic bacteria
  • Broad spectrum antimicrobial

    • Targets wide variety of pathogenic bacteria
  • Spectrum of activity
    Identifies the spectrum of activity --> therapeutic dosage determination
  • Sub-MIC or sub-lethal concentration
    • Useful for using the least drug concentration for the desired outcome
    • Cost effective and low toxicity
  • Antibiotic targets
    • Cell wall
    • Nucleic acid synthesis
    • Plasma membrane
    • Ribosomes
    • Metabolic pathways
  • AST results (MIC numbers)
    • MIC is below breakpoint = susceptible
    • MIC is between susceptible and resistant breakpoints = intermediate
    • MIC is above established breakpoint = Resistant
  • Breakpoint
    • Defines susceptibility and resistance to antibacterials
    • Determined by CLSI
  • Antibiotic or antimicrobial resistance

    Causes serious mortalities to regions all over the world
  • Factors contributing to antibiotic or antimicrobial resistance
    • Overuse and misuse of antibiotics in therapeutic use
    • Overuse and misuse of antibiotics in agriculture and rearing of livestock
    • Overuse and misuse of antibiotics due to leakage from pharma companies
    • Inappropriate use of antibiotics
    • Sub-therapeutic dosing
    • Patient's non-compliance with the recommended course of treatment
  • Mechanisms of antibiotic resistance
    • Enzymatic drug inactivation
    • Alteration of the target sites
    • Prevention of antibiotics access to target sites
  • Microbial death curve or survivor plots
    Measures microbial levels after exposure to sterilization methods either by calculating the death rates (death curve) or survival rates (survival plots)
  • Biological indicators (BI)
    Confirms successful sterilization process
  • Disinfection
    Reducing or destroying microbial load of an inanimate substrate
  • Sanitization
    Reduces microbial load of an inanimate substrates to safe public health levels
  • Sterilization
    Complete elimination of all vegetative cells, endospores and viruses from an inanimate substrate
  • Methods of sterilization
    • Terminal sterilization
    • Non-terminal sterilization
  • Terminal sterilization methods
    • Physical - Heat (Steam, Dry heat)
    • Physical - Radiation (Electromagnetic, Particulate, Accelerated electron)
    • Chemical - Gaseous (Ethylene oxide, Low temperature steam formaldehyde, Gas plasma)
    • Chemical - Liquid (Aldehydes, Peracetic acid, Hydrogen peroxide)
  • Filtration
    • For thermolabile solutions like ophthalmic solutions, antibiotics, vaccines, liquid vitamins, enzymes, culture media
    • Uses membrane filters to physically sieve out microorganism
  • All pharmaceutical preparations, medical products and devices should be sterile to prevent adverse events