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