Antibiotics mode of action Flashcards
What are physical controls of microbial growth? (2 points)
- Heat sterilization
- Radiation sterilisation
What are chemical controls of microbial growth? (3 points)
- Antiseptics (biological) and disinfectant (inanimate)
- Natural antimicrobials
- Synthetic antimicrobials
What are common examples of transmitted pathogens? (8 points)
- HIV
- Herpes simplex virus types 1 & 2
- HBV
- Streptococci
- Staphylococci
- Myobacterium tuberculosis
- Cytomegalovirus
- Some upper respiratory tract viruses
What are common forms of infection control? (4 points)
- Disinfecrtion of non-sterilisable surface and equipment
- Heat sterilization of all compatible equipment
- Handwashing techniques + appropriate antiseptics
- Combined with appropriate barrier techniques: masks, gloves and eye protection
What are disinfectants?
Strong chemical agents that inhibit or kill microorganisms
What are antiseptics?
Disinfecting agents with sufficiently low toxicity for host cells -> can be used directly on skin, mucous membranes, or wounds
What are sterilants?
- Kill both vegetative cells and spores when applied to materials for appropriate times and temperatures
What are antiseptics?
Disinfecting agents with sufficiently low toxicity for host cells
Where are antiseptics used? (3 points)
- Skin, mucous membranes or wounds
What is antisepsis?
- Use of chemical to destroy most pathogenic organisms on animate surfaces
What is antiseptic used for? (5 points)
- Treatment of skin infections
- Prevention of infections in cuts and wounds
- Cleaning the skin area of surgery from microorganisms
- Prophylaxis and treatment of infection sin mucosal areas such as mouth, nose and vagina that are open to the environment
- As a scrub for surgeons and the medical personnel
What are the 3 classifications of antiseptics?
- Those that denature proteins (cidal)
- Those that cause osmotic disruption of the cell (cidal)
- Those that interface with specific metabolic processes (growth arrest/static)
What is the mechanism of action of phenols, iodine, al cohols, aldehydes and mettalic compounds?
- Denature proteins and DNA bases
What is the mechanism of action of cationic detergents?
Interfere with plasma membrane’s permeability and cause leakage of enzyme, coenzyme and metabolites
What is the mechanism of action of oxidizing compounds?
- Oxidize functional molecules in the microorganisms
What are iodophores used for?
Used either as an antiseptic or disinfectant
What do iodophores do?
Kill vegetative bacteria, mycobacteria, fungi, lipid containing viruses (spores on prolonged use)
What are 2 examples of alcohols that are effective antiseptic and disinfectant agents?
- Ethyl alcohol and isopropyl alcohol
When alcohols are applied to the skin, by what % are bacterial numbers reduced?
90%
What do alcohols do? (2 points)
- Rapidly kill vegetative bacteria, fungi, and inactive lipophilic viruses
- Denature proteins and disturb the membrane permeability of bacteria
What is water soluble chlorohexidine digluconate used as?
An antiseptic
How does chlorohexidine work?
- Strongly absorbs to bacterial membranes and causes leakage of small molecules and precipitation of cytoplasmic proteins
What is the most common oxidising compounds that have been used as antiseptics?
Hydrogen peroxide
What type of bacteria are oxidising agents effective against?
- Vegetative bacteria, higher concentrations are sporicidal
