Module 6 Summary Flashcards
Suffix -icidal
Suffix means death
Used with a word root to indicate the micro-organism being kiled
eg. bactericidal, fungicidal, viricidal
Suffix -static
Suffix means that the microorganism is halted in its present state - it can no longer grow, but it is not killed.
Removal of the agent may allow growth to resume.
Used iwth root word to indicate microbe being affected.
Eg. bacteriostatic, fungistatic
Germicide means
an agent that kills germs (a generic term for referring to all microorganisms)
Fungicide means
An agent that kills fungi
Bactericide means
An agent that kills bacteria
Sporicide means
An agent that kills spores
Viricide means
An agent that kills viruses
sterilization
destroys ALL forms of microbial life; no degrees of sterilitiy - article is either sterile or not sterile
disenfection
destroys pathogens; other microbes and spores may survive; several levels; usually chemical
Terminal disinfection
disinfection procedure when patient leaves area - done before next patient arrives
antisepsis
disenfection mild enough for living tissue
sanitation
disinfection of eating utensils and dishes; mechnanical or chemical; agents used must not alter properties of food
cleaning
removal of soil/body secretions; does not imply disinfection; often soap and H2O
SUD
single use device - item used only once and then discarded (for ex - needles, catheters, syringes that have been in contact with body fluids)
Incineration
-terminal decontamination for biological or disposable waste (used needles, lab cultures, bandages, blood samples)
-burn at very high temperature → reduce everything to ash
-now usually done off-site → health care facility must adhere to TDG (Transportation of Dangerous Goods) regulations
Autoclave
-steam under pressure; “moist heat”
-optimum temperature: 121°C; pressure: 15 psi; time: 15 minutes, once temp. reached (longer if large load)
-re loading:
items on perforated tray
load loosely
dry goods on edge; lids ajar; jars, canisters, tubes → on sides
-testing for efficiency:
spore strips placed in autoclave (center and bottom)
place strips in culture medium after autoclaving → incubate → check for growth
growth means spores not killed; → autoclave not working properly
-items suitable for autoclaving:
surgical instruments
dressings (before use)
surgical gowns
anything that has to be sterile and can withstand the heat
not good for plastics (they melt) or rubber (gets sticky)
most items wrapped in protective packaging (cloth/paper) that steam can penetrate; indicator on package changes color during autoclaving so can distinguish sterile from nonsterile packages
if indicator has not changed color, don’t use materials in package
if packaging gets wet, items may no longer be sterile
Ethylene Oxide (ETO)
gas sterilization; no heat
use for heat-sensitive items (especially plastics)
large capacity
slow (8 hours); expensive; toxic to human tissue
Chemical Disinfection / Sterilization - Properties
desirable properties of “ideal” disinfectant:
broad spectrum
rapid action
resistance to inactivation by other material
nontoxic, odorless, nondestructive
residual action
user friendly
economical
Spaulding classification of items requiring disinfection/sterilization:
critical: items going into sterile area of body; must be sterile
semi-critical: items going into or touching area of body that is not sterile; no pathogens, but don’t have to be sterile
non-critical: items not going into body, but may touch body surface (e.g. beds, countertops); OK to have microbes; don’t want any that can be inhaled and cause infection
Resistance of microbes to disinfection:
vegetative bacteria - least resistant (easiest to destroy)
lipid viruses (except hepatitis B)
fungi
nonlipid viruses
tubercle bacilli (difficult to destroy)
bacterial spores - most resistant (most difficult to destroy)
Levels of disinfectants:
low level: kill vegetative bacteria and lipid viruses; other stuff may survive
intermediate level: kill everything except maybe nonlipid viruses and bacterial spores
high level: kill everything if sufficient time; essentially sterilants; when disinfectant washed off, item losses its true sterility (high level disinfectants not classified with sterilization procedures)
Groups of Chemical Disinfectants
detergents and soaps, alcohols, chlorine-containing, iodine, phenolic, glutaraldehyde, peroxygens
Low level disinfectants - Detergents & Soaps
surface active agents (aka surfactants, wetting agents) reduce surface tension so liquid can spread out instead of bead up therefore liquid gets into nooks and crannies
detergent vs soap: detergent is better wetting agent
soaps and detergents can be “regular” or antibacterial
if “regular”:
don’t kill microbes
do facilitate removal of microbes under force of running water, following mechanical scrubbing
quats (quaternary ammonium compounds):
act as detergents
some antimicrobial action: attach to microbial cell membrane causing lysis
low level
uses: cleaning; skin antisepsis
e.g: Zephiran
advantages:
economical
no bad odor; nonirritating
good wetting agent
kills gram + bacteria
disadvantages:
narrow microbial spectrum
inactivated by soaps,
detergents, fibers, hard H20, organic material
gram - rods may grow in it (Pseudomonas)
Intermediate level disinfectants - Alcohols (Ethanol and Isopropyl Alcohol)
intermediate level
optimum concentration = 70% (dilute with H20)
act by coagulating microbial protein”
main uses:
skin antisepsis (pre-venipuncture or pre-injection)
disinfect thermometers and tops of vials of injectable solutions
advantages of alcohols:
economical
nonirritating
kills vegetative bacteria, tubercle bacilli and lipid viruses
disadvantages:
if large number of microbes, not as effective
inactivated by organic material (probably ineffective against HBV in blood or other body fluid)
does not kill spores and nonlipid viruses
