Principle of Infection Flashcards
What is antisepsis? What are examples?
Reduction in the number of microorganisms and viruses, particularly potential pathogens, on living tissue
iodine, alcohol
What is aseptic? What are examples?
Refers to an environment or procedure free of pathogenic contaminants
Preparation of surgical field, handwashing, flame sterilization of laboratory equipment
What does ‘cide’ and ‘cidal’ mean?
indicates destruction of a type of microbe
- bactericidal, fungicidal, germicide
Germicides include ethylene oxide, propylene oxide and aldehydes
What is degerming? What are examples?
Removal of microbes by mechanical means
Handwashing, alcohol swabbing at site of injection
What is disinfection? What are examples?
Destruction of most microorganisms and viruses on living tissue
Phenolics, alcohols, aldehydes, soaps
What is pasteurisation?
Use of heat to destroy pathogens and reduce the number of spoilage microorganisms in food and beverages
- heat treatment is brief to minimize alteration of taste and nutrients, microbes still remain and eventually cause spoilage
Pasteurized milk and fruit juices
What is sanitisation? What are examples?
Removal of pathogens from objects to meet public health standards
Washing tableware in scalding water in restaurants
What does ‘stasis’ and ‘static’ mean? What are examples?
indicate inhibition, but not complete destruction, of a type of microbe
- bacteriostatic, fungistatic, virustatic
Germistatic agents include some chemicals, refrigeration and freezing
What is sterilisation? What are examples?
Destruction of all microorganisms and viruses in or on an object
Preparation of microbiological culture media and canned food
- Typically achieved by steam under pressure, incineration or ethylene oxide gas
What are the factors affecting selection of microbial methods?
Site to be treated
- choice of antimicrobial method depends on nature of site to be treated
Relative susceptibility of microorganisms
- microbes fall under a continuum from most susceptible to most resistant to antimicrobial agents
Environmental conditions
What are the methods for evaluating disinfectants and antiseptics?
phenol coefficient
- efficacy of various disinfectants and antiseptics calculated by ratio that compares a given agents ability to control microbes to that of phenol
use-dilution test
- several cylinders dipped into broth cultures of bacteria, dried at 37C, then the contaminated cylinders immersed into different dilutions of disinfectants and then inspected for growth of microorganisms
Kelsey-Sykes Capacity test
- suspension of bacterium is added to suitable concentration of chemical being tested. At predetermined times, samples of mixtures are moved into growth medium and observed for growth
= can be used for preservatives
In Use and simulated use tests
- swabs taken from actual objects before and after application of disinfectant or antiseptic. Swabs then inoculated into appropriate growth media and observed for growth
What are the considerations taken into account when looking at therapeutic drug monitoring for antimicrobials?
Malabsorption states
- e.g. other disease states may results in severe wasting of patients
Pharmacokinetic drug interactions
- e.g. inducers of cytochrome P-450 enzyme, particularly isoform enzymes of CYP3A subfamily (ii) inhibition of absorption of other drugs
Drug-disease interactions, e.g. renal problems, liver problems
What is systemic inflammatory response syndrome (SIRS)? What is it caused by? What can it lead to?
systemic inflammatory response syndrome
- inflammation throughout the whole body
- exaggerated defense response of the body to a noxious stressor (infection, trauma, surgery, acute inflammation, ischemia or reperfusion, or malignancy,)
Infections provoking SIRS produce the syndrome sepsis
sepsis
- sepsis is a syndrome defined aslife-threatening organ dysfunction due to a dysregulated host response to infection
- immune system overreacts to an infection and starts to damage your body’s own tissues and organs.
