Chapter 11, Microbial control
Which of the following are examples of chemical agents used to control microbes?
Alcohols Phenolics Heavy metals Oxidizers Halogens Aldehydes
Phenolics typically kill microbes by
Denaturing metabolic enzymes Disrupting the cell wall Disrupting the cell membrane
Iodine compounds are commonly used for
Disinfection of medical equipment Treatment of skin wounds Antisepsis of skin
The property of having antimicrobial effects in exceedingly small amounts belongs to which class of chemicals?
Heavy metals
is energy emitted from atomic activities and dispersed at high velocity through matter or space.
Radiation
Alcohols are effective against?
Resistant bacteria Enveloped viruses
Which of the following type of materials can be more reliably disinfected with a germicide?
Smooth Objects
What is true about soaps?
Soaps are only weakly microbicidal. Some bacteria can grow on soap as a nutrient source. Soaps help to mechanically remove surface debris. Soaps have great germidical value when mixed with iodine. Soaps can destroy few common hospital pathogens.
Which of the following are some of the desirable qualities in a germicide?
Solubility in a solvent Broad-spectrum action Selective toxicity Penetrating ability Rapid action
A process that completely removes or destroys all viable microorganisms, including viruses, from an object or habitat is referred to as .
Sterilization
is the destruction of all microbial life; Destroys most microbial life, thus reducing contamination
Sterilization; Disinfection
An agent's effect on cells is known as its mode of action.
True
Moist heat requires shorter exposure times and lower temperatures than dry heat.
True
True or false: The primary targets of microbial control are microorganisms that cause infection or spoilage.
True
True or false: The straining of a fluid or air through a membrane to trap microorganisms is known as filtration.
True
______ is the destruction of most microbes using chemicals on a living surface such as the skin.
antisepsis
Antimicrobial solutions with water as the solvent are called ________, whereas antimicrobial solutions with alcohol or water-alcohol mixtures as the solvent are called _________.
aqueous, tinctures
Sodium hypochlorite is also known as
bleach
spectrum action is a desirable characteristic of a germicide.
broad
involves the permanent termination of a particular organism's vital processes, and special qualifications are often needed to define and delineate this phenomenon in microbes.
death, microbial death, or cell death
Iodine compounds typically kill microbes by
denaturing proteins
chlorhexidine kills microbes through
denaturing proteins disrupting cell walls disrupting cell membranes
Cationic detergents typically work by:
disrupting the cell membrane
A process that completely removes or destroys all viable microorganisms, including viruses, from an object or habitat is referred to as disinfection.
false
True or false: Household cleaners are often alcohol based.
false
True or false: Iodine compounds are commonly used for household cleaning.
false
True or false: Only a few microorganisms are killed by iodine even if proper concentrations and exposure times are used.
false
True or false: The phenol coefficient quantitatively compares the effectiveness of a chemical to that of alcohol.
false, phenol
The primary targets of microbial control are microorganisms that cause ______ or ______.
food spoilage & disease
As the most extensively used chlorine compounds, hypochlorites are used for
household cleaning food equipment sanitation swimming pool treatments wound treatment and skin cleansing
The use of sugar or salt to preserve food creates a __________ environment for the bacteria in the foods.
hypertonic
Plasmolysis of bacteria in foods occurs when high concentrations of salt or sugar are added to the foods creating a
hypertonic environment
Gaseous and liquid chlorine compounds are mostly used for
large-scale water disinfections
Quaternary ammonium compounds are considered to be
low-level disinfectants
Which of the following heavy metals are still used in germicidal preparations?
mercury silver
The property of having antimicrobial effects in exceedingly small amounts is called a(n) _____ action.
oligodynamic
_________ ___________ quantitatively compares the effectiveness of a chemical disinfectant to that of phenol.
phenol coefficient
methods for controlling microorganisms include heat, pressure, and radiation.
physical methods
Iodine compounds typically kill microbes by denaturing
proteins
is an alkaline compound made by combining the fatty acids in oils with sodium or potassium salts.
soap
Alcohols are not effective against naked viruses and bacterial
spores
One of the most widely used phenolics, banned from consumer products in 2017 over concerns of development of resistance, is
triclosan
Alcohol is most commonly used as a degerming agent for the skin
true
Chlorhexidine targets cell membranes and proteins
true
Death is characterized by the stopping of all metabolic activity of a cell
true
Disinfection removes all vegetative pathogens
true
Iodine compounds commonly used for treatment of wounds and skin cleaning
true
Iodine may kill all classes of microbes if used appropriately
true
True or false: Chlorhexidine typically kills microbes by disrupting the cell membrane or denaturing proteins.
true
True or false: Hypochlorites are probably the most extensively used of all chlorine compounds; however, chloramines are being employed more frequently as alternatives in treating water supplies due to concerns regarding the formation of cancer-causing substances.
true
True or false: Iodine compounds can be sporicidal if used properly.
true
True or false: The two primary iodine preparations are free iodine and iodophors.
true