Flashcards in Chapter 9 Deck (172)
_____ destroys all viable microbes, endospores.
_____ is not for living tissue.
_____ destroys vegetative pathogens, not endospores.
_____ is not 100% (not sterilization)
_____ is mechanical removal of microbes to safe levels.
Dishwashing is an example of ___.
_______ is the reduction of microbe numbers on skin.
Hand sanitizer and soap are examples of _____.
Antisepsis is used for _____.
Microbial Resistance from the highest resistance to the least resistance.
staphylococcus & pseudomonas
most gram negative bacteria
fung and fungi spores
most gram positive bacteria
_____ are the target of sterilization
Term ending in -cidal means to ____.
Bleach, iodine, or heat are forms of ______.
_____ are chemical agents capable of destroying endospores.
Alcohol and surgical hand scrubs are agents for ______.
A _____ is a chemical agent that destroys bacteria except for those in the endospore stage.
A ____ is a chemical that can kill fungal spores, hyphae, and years.
A ___ is any chemical known to inactive viruses, especially on living tissues.
A term ending in -static means the ability to prevent _______.
A ____ is an agent capable of destroying bacterial endospores.
A sporicidal agent can also be a sterilant because it can destroy the most resistant of all ____.
______ and microbicide are additional terms for chemical agents that kill microorganisms.
_____ agents prevent the growth of bacteria on tissues or on objects in the environment.
____ agents chemically inhibit fungal growth.
Materials used to control microorganisms in the body (antiseptics and drugs) often have ___ effects because many microbicidal compounds can be highly toxic to human cells.
_____ is defined as the growth of microorganisms in the blood/tissues.
_____ prevents the entry of infectious agents into sterile tissues (prevent infection).
______ are the range of methods depending on task.
Chemical agents called antiseptics are applied directly to _____, wounds, and surgical incisions to destroy or inhibit vegetative pathogens.
exposed body surfaces
Factors affecting Death Rate
1. Number of microbes present
2. The nature of the microbe population
3. Temperature and pH of the environment
4. The concentration (dose, intensity) of the agent
5. The mode of action of the agent
6. The presence of interfering organic matter
The four targets of antimicrobials.
1. The cell wall
2. The cell membrane
3. Cellular synthetic processes
4. Protein Function
____ is a phenomenon that involves the permanent termination of an organsims's vital processes
A chemical agent can damage the cell wall by blocking its synthesis or _____ the cell wall.
Effects of Impacting cell wall
By disrupting cell membranes there is a loss of ______ which causes ____.
Some antimicrobial processes can affect ______.
cellular synthetic processes
Some antimicrobials affect cellular synthetic processes by interrupting of protein synthesis impacts _____ and ____.
metabolism and multiplicationSome antimicrob
Some antimicrobials affect cellular synthetic processes which cause ________.
damage to genetic material (causing mutations)
Most _____ need to be folded to function.
Protein _____ inactivates protein function.
Heat, alcohol, acids, and other compounds can also disrupt ______ leading to a loss in function.
_____ is a method of physical control.
_____ temperatures are microbicidal.
_____ temperatures are microbistatic.
Methods of controlling microorganisms into two broad categories: ____ and ____.
chemical and physical
Moist heat and dry heat differ in their modes of ____ as well as in their ____.
____ heat operates at lower temperatures and faster working than ____ heat.
Although many cellular structures are damaged by moist heat, its most microbicidal effect is the _____ and _____ of proteins, which quickly and permanently halts cellular metabolism.
coagulation and denaturation
____ heat dehydrates cell and denatures proteins. The lack of water actually increases the stability of some protein conformations, necessitating the use of higher temperatures when ____ heat is employed as a method of microbial control.
_____ heat at very high temperatures, oxidizes cells, burning them to ash.
i.e.. when an inoculating loop in incinerated
There sterilization by moist and dry heat takes place at ____ temperature.
With moist heat it takes ____ minutes to sterilize.
With dry heat it takes ____ minutes to sterilize.
_______ exhibit the greatest heat resistance.
The destruction of spores usually requires temperatures above ____.
Vegetative cells and fungi are the ____ heat resistant to both moist and dry heat.
Vegetative cells vary in their heat sensitivity. Death times with moist heat range from 50C for 3 minutes (Neisseria gonorrhoea) to ___C for ___ minutes for Staphylococcus aureus.
____ are surprisingly resistant to heat, with a tolerance range extending from 55C for 2-5 minutes (_____) to 60C for 600 minutes (_______).
hepatitis A virus
Heat treatment of perishable substances must render the product free of agents of spoilage or disease without affecting the ____ and ____ of processing.
speed and cost
______ is the shortest length of time required to kill all microbes at a specified temperature.
Thermal death time (TDT)
______ is the lowest temperature required to kill all microbes in a sample in 10 minutes.
Thermal death point (TDP)
The three common methods of moist heat.
1. Steam under pressure
3. Boiling water
_____ is a technique in which heat is applied to liquids to kill potential agents of infection and spoilage, while at the same time retaining the liquids flavor and food value.
Autoclaves are used for ____.
Autoclaves cannot sterilize just with steam so it must be steamed ______. An _____ in pressure = higher temperatures than possible without increased pressure.
Autoclaves sterilize at ___ psi's, at 121C, for ___ minutes.
______ kill all endospores.
Home pressure cookers function on the same basic principle as _____.
Heat resistant materials such as glassware, cloth (surgical dressings), metallic instruments, liquids, paper, some media, and some heat resistant plastics are sterilized by _____.
Autoclaves are ineffective for sterilizing substances that repel moisture (______) and for those that are harmed by it (______).
oils and waxes
_____ disinfects liquids.
Pasteurization may not kill ____.
Pasteurization does not kill _____.
Boiling water is for disinfection, not ____.
To disinfect materials, they must be exposed to boiling water for _____.
Boiling water causes ____.
Hot air sterilization is a method of _____ heat that takes place in an oven.
Hot air sterilization is used for _____ items and it takes hours.
Hot air sterilization destroys ____.
_____ is a form of dry heat with a flame.
_____ turns microbes to ashes and gas.
In micro labs ____ is a common practice because it destroys everything.
The principal benefit of _____ is to slow growth of cultures and microbes in food during processing and storage. I merely slows the activities of most microbes, not killed (rare).
Freezing temps from ____ to ____ are often used in research labs to preserve cultures of bacteria, viruses, and fungi for long periods.
-70C to -135C
______ grow slowly at freezing temperatures and can secrete toxic products.
Vegetative cells directly exposed to normal room air gradually become dehydrated or ____.
Spirochete of _____ and Neisseria gonorrhoeae die after a few hours of air drying or ______.
Endospores of Bacillus and _____ are viable for thousands of years under extremely arid conditions.
Freeze drying is called _______, which is a common method of preserving microorgansims and other cells in a viable state for many years.
Chilling, freezing and desiccation should not be construed as method of ____ or ____.
disinfection or sterilization
_____ is defined as energy emitted from atomic activities and dispersed at high velocity through matter of space.
The forms of radiation suitable for microbial control gamma rays, ____, and _____.
Ionizing radiation includes _____ and ____.
gamma rays and x rays
Nonionizing radiation includes _____.
Radiation is used to destroy microbes or _____ that might be present in or on food.
_____ ability of radiation is related to wavelength of the radiation.
Radiation is mot useful for surfaces such as ____, ____, and tables.
Ionizing radiation is _____ energy and _____ penetrating.
______ radiation breaks the DNA backbone causing structural damage.
______ radiation is used for foods, poultry, drugs/medical supplies, mail.
_____ radiation damages DNA (thymine dimers)
_____ radiation is not as penetrating as _____ radiation.
_____ radiation is used for disinfection not sterilization.
_____ radiation works on endospores with long exposure.
_____ radiation is used for hospital rooms, schools, food prep areas, and dental offices.
______ pass liquid or gas through a filter with small pore size.
Filtration is a method of ____ removal.
No heat is involved with ____.
Filtration is an efficient method of removal of _______.
High efficiency particulate air (HEPA) filters are used in hospital rooms and sterile rooms which are a form of _____.
Microbiological ____ are thin membranes of cellulose acetate, polycarbonate, and a variety of plaster materials (teflon, nylon) whose pore size can me carefully controlled and standardized.
Adding large amounts of slat or sugar to foods creates a hypertonic environment for bacteria in the foods causing ______ and making it impossible for the bacteria to ____.
Picking, smoking and drying foods have been used for centuries to _____.
Osmotic pressure is never a _____ technique.
Antimicrobial chemicals occur in liquids, gaseous, or even solid state, and they range from disinfectants and ______ to sterilants and preservatives.
Approximately ____ different antimicrobial chemical agents are manufactured. Approximately ____ are used routinely in health care and the home.
_____ solutions are when chemicals are dissolved in pure water as the solvent.
____ are chemicals dissolved in pure alcohol or water-alcohol mixtures.
Germicides are evaluated in terms of their ______ in destroying microbes in medical and dental settings.
Factors that affect the germicidal activity of chemicals.
1. Nature of microorgansims being treated
2. Nature of the material being teated
3. Degree of contamination
4. Time of exposure
5. Strength and chemical action of the germicide
Mycobacterium tuberculosis requires a concentration of ____ and ____ for chemical destruction.
50 ppm and 50 seconds
Entamoeba cysts (protozoa) requires a concentration of ____ and _____ for chemical destruction.
0.1 ppm and 150 minutes
Hepatitis A virus requires a concentration of ____ and ____ for chemical destruction.
3 ppm and 30 minutes
The agent ______ is used on Mycobacterium tuberculosis, Entamoeba cysts, and Hepatitis A virus.
The agent _____ is used on Staphylococcus aureus, Escherichia coli, and Poliovirus.
Staphylocoocus aureus requires a concentration of ______ and ____ for chemical destruction.
70% and 10 minutes
Escherichia coli requires a concentration of ______ and ____ for chemical destruction.
70% and 2 minutes
Poliovirus requires a concentration of ______ and ____ for chemical destruction.
70% and 10 minutes
Halogens affect _____.
Two types of halogens are ______ and _____.
iodine and chlorine
____ is a topical antiseptic which is not very soluble, usually combined with soluble agents in a "tincture"
_____ is a disinfectant that kills bacteria, endospores, fungi, and viruses.
_______ mode of action is highly toxic oxygen free-radicals.
When hydrogen peroxide is used as an antiseptic, ____ wound cleansing, skin antiseptid.
Higher concentrations of ____ work better on endospores. Use on surfaces only, not skin.
______ disrupt cell walls and membranes and coagulate proteins.
____ is a phenolic, as well as the triclosan found in some antibacterial soaps.
_____ is in products such as clothing, kitchenware, furniture as well as antibacterial soaps/body washes, toothpastes, and some cosmetics.
Animal studies have shown that ___ alters hormone regulation.
Triclosan is not known to have effect on ____.
Triclosan may contribute to _____ resistance.
FDA is engaged in an ongoing scientific and regulatory review of _____.
____ targets cell membranes and protein structure.
Chlorhexidine is a bactericidal for ______, but not endospores.
both gram positive and gram negative bacteria
Alcohols are most effective at concentrations of _____ in water.
_____ kill by dissolving cell membranes.
____ coagulate proteins.
Only ______ and _____ have the activity suitable for microbial control.
ethanol and isopropanol
Alcohols ____ endospores.
do not kill
____ contain quaternary ammonia compounds (QUATS)
Detergents provide ____ disinfection.
Detergents disrupt _____.
Plain soap is a method of ____ removal.
Heavy metal compounds antimicrobial effects are in ______.
very small amounts
Heavy metal compounds ____ proteins.
Drawbacks to using metals in microbial control are that it is very ____ to humans and often causes allergic reactions. Large quantities of biological fluids and wastes ____ their actions.
Microbes can develop ____ to heavy metal compounds.
Aldehydes ____ proteins.
Types of disinfectants include aldehydes and ____.
Two types of aldehydes are ____ and ____.
glutaraldehyede (hospital instruments)
Glutaraldehyde is somewhat ___, especially with increased pH and temperature.
Formaldehyde is extremely ____ and is irritating to skin and mucous membranes.
Ethylene oxide is ____ and must be combined with high percentage of carbon dioxide or fluorocarbon.
Gaseous chemosterilants ___ proteins, and alter DNA replication.
Gaseous chemosterilants are chemicals that ____ in a closed chamber without heat.
Ethylene oxide kills ____ .
all microbes and endospores
Hospitals use _____ to sterilize large heat sensitive items.
Ethylene oxide is a _____.
Bacterial endospores and prions are in the ____ category.
____ are proteinaceous infectious particles . (BSE, CJD)
What is the best way to ensure endospore killing?
use hydrogen peroxide