sterilization

Cards (45)

  • Sterilization
    The killing or removal of all viable organisms from a growth medium or surface including endospores and viruses
  • Decontamination
    The treatment of an object or surface to make it safe to handle
  • Disinfection
    Directly targets pathogens although it might not eliminate all microorganisms
  • Methods for inhibiting rapid microbial growth

    • Sterilization
    • Decontamination
    • Disinfection
  • Disinfectants
    Specialized chemical or physical agents that can kill microorganisms or inhibit microbial growth
  • Microbial control in vivo is much more difficult
  • Bactericidal agents

    Kill microorganisms
  • Bacteriostatic agents

    Inhibit microbial growth
  • Bacteriolytic agents

    Some bactericidal agents are also bacteriolytic agents
  • Depending on the type of microorganism or pathogen to be controlled, the terms can also be applied to fungi (e.g., fungicidal) and viruses (e.g., viricidal)
  • Minimum inhibitory concentration (MIC)

    Determines the smallest amount of agent needed to inhibit the growth of the test organism
  • Disk diffusion technique

    A technique for measuring antimicrobial activity
  • Categories of chemical antimicrobial agents

    • Antimicrobial products used to control microorganisms in industrial and commercial environment
    • Products designed to prevent growth of human pathogens in inanimate environments and on external body surface
  • Sterilants
    Destroy all forms of microbial life, including endospores
  • Disinfectants
    Kill microorganisms but not necessarily endospores and are used on inanimate objects
  • Sanitizers
    Agents that reduce but may not eliminate microbial numbers to levels considered to be safe
  • Antiseptics and germicides

    Chemical agents that kill or inhibit growth of microorganisms and that are nontoxic enough to be applied to living tissue
  • Only sterilants are effective against bacterial endospores
  • Some bacteria such as Mycobacterium tuberculosis are resistant to the action of common disinfectants because of the waxy nature of their cell wall
  • Categories of antimicrobial agents

    • Synthetic agents
    • Antibiotics
  • Selective toxicity

    Ability to inhibit or kill a pathogen without affecting the host
  • Growth factor analogs

    Structurally similar to growth factors but do not function in the cell
  • Growth factor analogs

    • Analogs similar to vitamins, amino acids, and other compounds
  • Sulfa drugs

    First widely used growth factor analogs that inhibit growth of bacteria
  • Isoniazid
    A growth analog effective only against Mycobacterium that interferes with synthesis of mycolic acid, a mycobacterial cell wall component
  • Nucleic acid base analogs

    Have been formed by the addition of bromine or fluorine atom to block nucleic acid synthesis, used in treatment of viral and fungal infections
  • Quinolones
    Antibacterial compounds that interfere with DNA gyrase, preventing the supercoiling of DNA
  • Antibiotics
    Naturally occurring antimicrobial drugs produced by microorganisms
  • The majority of antibiotics (>99%) are not clinically useful without structural modifications in the laboratory, a process that creates semi-synthetic antibiotics
  • Broad-spectrum antibiotics

    Find wider medical use than narrow-spectrum antibiotics
  • Novel antibiotics continue to be discovered and/or synthesized by modifying current drugs
  • β-Lactam antibiotics

    One of the most important groups of antibiotics, including penicillins and cephalosporins, over half of all antibiotics used worldwide
  • Penicillins
    Discovered by Alexander Fleming, primarily effective against gram-positive bacteria, some synthetic forms are effective against some gram-negative bacteria, target cell wall synthesis
  • Cephalosporins
    Produced by fungus Cephalosporium, same mode of action as the Penicillins, commonly used to treat gonorrhea
  • Aminoglycosides
    Useful against Gram negative bacteria, target the 30S subunit of the ribosome, not commonly used today due to neurotoxicity and nephrotoxicity
  • Macrolides
    Example: erythromycin, broad-spectrum antibiotic that targets the 50S subunit of ribosome
  • Tetracyclines
    Widespread medical use in humans and animals, broad-spectrum antibiotics, inhibiting almost all gram-positive and gram-negative bacteria, inhibits functioning of 30S ribosomal subunit
  • Daptomycin
    Depolarizes bacterial cell membranes and is used mainly against gram-positive bacteria
  • Platensimycin
    Inhibits a key enzyme in bacterial fatty acid biosynthesis, thus disrupting lipid biosynthesis
  • Antimicrobial drug resistance

    The acquired ability of a microorganism to resist the effects of an antimicrobial agent to which it is normally susceptible