Chapter 9 Quiz review

The suffixes that indicate that the agent kills or permanently inactivates a particular type of microbe

-cide and -cidal

The suffixes that indicate that an antimicrobial agent inhibits microbes

-stasis and -static

Methods of pasteurization:

1. The historical (batch) method 2. Flash pasteurization 3. Ultrahigh-temp pasteurization --These methods differ in their combinations of temperature and time of exposure

Four methods for evaluating the effectiveness of a disinfectant or antiseptic are:

1. The phenol coefficient 2. The use-dilution test 3. The Kelsey-Sykes capacity test 4. The in-use test

Factors affecting the efficacy of antimicrobial methods:

1. The site to be treated 2. The relative susceptibility of microorganisms 3. Environmental conditions

Under certain circumstances, microbes can be controlled using:

1. Ultrahigh-temp sterilization 2. Dry-heat sterilization 3. Incineration 4. Refrigeration 5. Freezing

Which of the following disinfectants contains alcohol?

A tincture of bromine

__________ are high-level disinfectants that cross-link organic functional groups in proteins and nucleic acids.

Aldehydes

Which of the following statements is true concerning the selection of an antimicrobial agent?

An ideal antimicrobial agent is stable during storage; an ideal antimicrobial agent is fast acting; ideal microbial agents do not exist.

___________ which include antibiotics, semisynthetics and synthetics are compounds that are typically used to treat diseases but can also function as intermediate level disinfectants

Antimicrobials

Which of the following adjectives best describes a surgical procedure that is free of microbial contaminant?

Aseptic

Which standard level designated by the CDC is most strict when working with microbes in the lab?

BSL-4

The spores of which organism are used as a biological indicator of sterilization?

Bacillus stearothermophilus

For what do humans use antimicrobial enzymes?

Commercially in food preservation and as a noncaustic, nondestructive way to eliminate prions on medical instruments

A sample of E. coli has been subjected to heat for a specified time, and 90% of the cells have been destroyed. Which of the following terms best describes this event?

Decimal reduction time

The time required to destroy 90% of the microbes in a sample

Decimal reduction time (D)

Antimicrobial methods involving drying are:

Dessication

Biosafety level 3 includes:

Double sets of entry doors

In practical terms which of the following statements provides the definition of sterilization?

Eliminates all organisms and their spores or endospores

Which antimicrobial chemical has been used to sterilize spacecraft?

Ethylene oxide

Which of the following chemicals is active against bacterial endospores?

Ethylene oxide

__________of microbial control, which include ethylene oxide, propylene oxide, and beta-propiolactone, are high level disinfecting agents used to sterilize heat sensitive equipment and large objects.

Gaseous agents

Which filters remove microbes and particles from air?

HEPA (high efficiency particulate air) filters

___________ are used as intermediate-level disinfectants and antiseptics to kill microbes in water or on medical instruments or skin.

Halogens

For most applications these have been superseded by less toxic alternatives:

Heavy metal ions

____________ such as arsenic, silver, mercury, copper and zinc are low-level disinfectants that denature proteins.

Heavy metal ions

Which of the following substances is least toxic to humans?

Hydrogen peroxide

Which of the following substances would most effectively inhibit anaerobes?

Hydrogen peroxide

The permanent loss of reproductive capacity

Microbial death

Measures the efficacy of an antimicrobial agent

Microbial death rate

________ (wavelengths longer than 1 nm) is less effective in microbial control, although UV light causes pyrimidine dimers, which can kill affected cells

Nonionizing radiation

A method of heating food to kill pathogens and control spoilage organisms without altering the quality of the food

Pasteurization

A process using heat to kill pathogens and control microbes that cause spoilage of food & beverages

Pasteurization

Which of the following disinfectants acts against cell membranes?

Phenol

Chemically modified phenol molecules that are intermediate to low-level disinfectants that denature proteins and disrupt cell membranes in a wide variety of pathogens.

Phenolics

Which class of surfactant is most soluble in water?

Quaternary ammonium compounds

______ includes high-speed subatomic particles and even more energetic electromagnetic waves released from atoms.

Radiation

The eradication of microorganisms and viruses; the term is not usually applied to the destruction of prions

Sterilization

__________ include soaps, which act primarily to break up oils during degerming and detergents such as quats which are low-level disinfectants

Surfactants

The microbial death rate is used to measure

The efficiency of a detergent; the efficiency of an antiseptic; the efficiency of sanitization techniques

Which method for evaluating the effectiveness of a disinfectant provides a more accurate determination of efficacy under real-life conditions?

The in-use test

The lowest temp that kills all cells in a broth in 10 minutes

Thermal death point

The time it takes to completely sterilize a particular volume of liquid at a set temp

Thermal death time

Which of the following functions most like an autoclave?

a pressure cooker

_________ are intermediate level disinfectants that denature proteins & disrupt cell membranes; they are used either as 70% to 90% aqueous solutions or in a tincture, which is a combination of an alcohol and another antimicrobial chemical

alcohols

Antimicrobial agents destroy microbes either by ____________ or by ____________

altering their cell walls and membranes --- interpreting their metabolism and reproduction via interference with proteins & nucleic acids

Many organisms use ______________ to combat microbes.

antimicrobial enzymes

The inhibition/killing of microorganisms (particularly pathogens) on skin or tissue by the use of a chemical

antisepsis

Environment or procedure is free of contamination by pathogens

aseptic

Uses steam heat under pressure to sterilize chemicals and objects that can tolerate moist heat

autoclave

The removal of microbes from a surface by scrubbing

degerming

Although their exact mode of action is unknown, halogens are believed to _________

denature protein

The preservation of beef jerky from microbial growth relies on which method of microbial control?

desiccation

Which of the following substances or processes kills microorganisms on laboratory surfaces?

disinfectants

the use of agents to inhibit microbes on inanimate objects

disinfection

Which of the following types of radiation is more widely used as an antimicrobial technique?

electron beams

These gases are explosive and potentially carcinogenic:

ethylene oxide, propylene oxide, and beta-propiolactone,

when used as a microbial control method, _________ is the passage of air or a liquid through a material that traps and removes microbes.

filtration

A 37% aqueous solution of formaldehyde:

formalin

A company that manufactures an antimicrobial cleaner for kitchen counters claims that its product is effective when used in a 50% water solution. By what means might scientists best verify this statement?

in-use test

Give examples of a halogen:

iodine, chlorine, bromine, fluorine

___________ (wavelengths less than 1nm) produces ions that denature important molecules and kill cells.

ionizing radiation

Used for the long-term preservation of cells or microbes:

lyophilization (freeze drying)

Some _________ have pores small enough to trap the smallest viruses.

membrane filters

The high _______ exerted by hypertonic solutions of salt or sugar can preserve foods such as jerky and jams by removing the water from microbes that they need to carry out their metabolic functions

osmotic pressure

___________ such as hydrogen peroxide, ozone, and peracetic acid are high-level disinfectants and antiseptics that relase oxygen radicals, which are toxic to many microbes, especially anaerobes

oxidizing agents

The reduction of a prescribed number of pathogens from surfaces and utensils in public places

sanitization

Which of the following terms best describes the disinfecting of cafeteria plates?

sanitization

Dessication is used:

to preserve food