Disinfectants & More! Flashcards
Chemical germicides
substance designed to reduce number of pathogens
Disinfectant
germicide for use on non-living things (surfaces)
Examples of disinfectants
bleach, H2O2 (hydrogen peroxide), isopropyl alcohol, ethyl alcohol
Effect of disinfection
destroys vegetative pathogens on a surface, usually with liquid chemical agents
reduces or inhibits growth, does NOT sterilize
Antiseptics
Germicides designed for use on living tissues (mouthwash or betadine)
Use-Dilution Tests
determined effectiveness of disinfectants against pathogens
the more the chemical can be diluted and still be effective, the higher the rating
Sanitation
cleans and disinfecta
Sterilisation
highest level of pathogen control that destroys ALL forms of life (including endospores) in or on a material
Major categories of disinfectants
Phenolics, oxidising agents, alcohols, halogens, and surfactants
Phenolics
active ingredients in some household disinfectants, mouthwashes, soaps, and hand washes
What is Phenol?
A carbolic acid; present in Lysol
What is Bisphenol?
Phisohex are two phenolic groups connected by a bridge
Alcohols
sometimes used as disinfectants, but more often as antiseptics (used on living tissue)
Oxidising agents
hydrogen peroxide (H2O2) and house bleach (sodium hypochlorite solution)
Halogens
strong oxidising agents such as, betadine
commonly used as disinfectants
Examples of halogens
Fluorine (fluoride in toothpaste), chlorine, bromine, iodine (betadine solution)
Surfactants
Emulsify oils (soaps and detergents)
Resistance to chemical biocides (most to resistant to least resistant)
Endospores
Mycobacteria
Gram (-)
Viruses without envelopes
Gram (+)
Viruses with envelopes
Germ theory of disease
microorganisms cause disease
Antibiotics
NATURAL anti microbial agents (penicillin)
Antimicrobials or antimicrobics
synthetic agents used to treat bacterial infections
Zone of inhibition
area showing antibiotic susceptibility or NO GROWTH
Concentration gradients
established by antibiotics as they diffuse through the agar
Minimum inhibitory concentration (MIC)
LOWEST concentration of antibiotic for which there is no growth
Disk diffusion test
Measures effectiveness of antimicrobics against pathogens
Susceptible
Bacteria affected by antibiotics
Resistant
Bacteria NOT affected by antibiotics
Examples of Antibiotics
Ampicillin, chloramphenicol, penicillin, streptomycin, tetracycline, trimethoprim, vancomycin (commonly used for tests)
Fluid Thioglycollate Medium
liquid medium that allows the growth of anaerobic and microaerophilic bacteria
Anaerobic Jar
Used to create anaerobic, microaerophilic, CO2-enriched conditions depending on specific needs of bacteria
Aerotolerance
Ability or inability to live in presence of O2 (do not use O2 for growth, but can tolerate its presence)
Obligate (strict) aerobes
Organism that require O2 for respiration, usually grow at top where it’s most plentiful
Facultative anaerobes
Grow in presence or absence of O2
Obligate (strict) anaerobes
Grow in the absence of O2, usually at the bottom
