Chapter 11: Physical and Chemical Agents for Microbial Control

A sterile object is free of which of the following? Everything except endospores All viable microorganisms except viruses All viable microorganisms and viruses Almost all viable microorganisms and viruses

All viable microorganisms and viruses

_____ is a term referring to a condition free of pathogenic microorganisms or a procedure or process designed to prevent entry of infectious agents.

Asepsis

The microbial agents that are least resistant to physical and chemical control methods include which of the following? Protozoan cysts Bacterial endospores Bacterial vegetative cells Enveloped viruses

Bacterial vegetative cells Enveloped viruses

Contaminants that can have far-reaching effects if not adequately controlled include which of the following? Bacterial vegetative cells Autoclaved endospores Fungal hyphae and spores

Bacterial vegetative cells Fungal hyphae and spores

Which typically describes cold temperatures? Bactericidal Bacteriostatic

Bacteriostatic

_____ spectrum action is a desirable characteristic of a germicide.

Broad

Antimicrobial agents affect microbial DNA in what ways? Cause mutations Stop peptide bond formation Break double helix Prevent transcription Inhibit replication

Cause mutations Prevent transcription Inhibit replication

Which is the major cellular structure affected by alcohols? Cell wall Flagella Ribosomes Cell membrane

Cell membrane

The effect of a germicide is affected by which of the following factors? Concentration of germicide Material being treated Toxicity to human and animal tissues Time of exposure to germicide Contamination with organic matter Chemical action of germicide Nature of microbial population

Concentration of germicide Material being treated Time of exposure to germicide Contamination with organic matter Chemical action of germicide Nature of microbial population

Microbes that are present at any given time and place that are undesirable or unwanted are known as which of the following? Endospores Cysts Contaminants

Contaminants

The primary targets of microbial control are microorganisms that cause which of the following? Antibiotic production Disease Microbial antagonism Food spoilage

Disease Food spoilage

Alcohols are most effective at destroying which of the following? Enveloped viruses Nonenveloped viruses Bacterial endospores Vegetative bacteria

Enveloped viruses Vegetative bacteria

What is the process of straining a fluid or air through a membrane to trap microorganisms? Radiation Pasteurization Filtration

Filtration

How are many cultures of microbes routinely preserved? Dessication Solid agar plates Freezing Liquid culture

Freezing

Which are not commonly used sanitizers? Detergents Soaps Germicides Alcohols

Germicides Alcohols

Which is the most prominent among antimicrobial physical agents? Heat Antibiotics Filtration Radiation

Heat

Which of the following are examples of physical agents or mechanical means used to control microbes? Heat Radiation Filtration Phenolics Germicide

Heat Radiation Filtration

Which of the following is the practical definition of microbial death? Loss of motility Inability to reproduce Altered appearance of cells Altered virulence of cells

Inability to reproduce

Sterilization methods are usually reserved for which of the following? Living tissue Food utensils Inanimate objects

Inanimate objects

_____ is the process of bombardment with radiation at the cellular level to control microbes.

Irradiation

Which is the definition of sepsis? It is growth of microorganisms in the water supply. It is growth of microorganisms in the blood or other tissues. It is death of tissue due to microbial growth.

It is growth of microorganisms in the blood or other tissues.

Which word is typically used to describe the size of bacterial population? ID50 Growth Colony Load

Load

When microbes are treated with temperatures that exceed their maximum growth temperature, the condition is described as which of the following? Microbistatic Microbicidal

Microbicidal

Which are goals of pasteurization? Reduction of microbial load Retention of liquid qualities Sterilization of liquid Destruction of endospores

Reduction of microbial load Retention of liquid qualities

Which of the following best describes any cleansing technique that removes debris, microorganism, and toxins resulting in a decreased potential for infection and spoilage? Degermation Antiseptic Sepsis Sanitization

Sanitization

Which of the following best describes any cleansing technique that removes debris, microorganism, and toxins resulting in a decreased potential for infection and spoilage? Sepsis Sanitization Antiseptic Degermation

Sanitization

Antimicrobial chemicals can exist in what physical states? Low-level Solid High-level Gas Liquid

Solid Gas Liquid

Chemical agents that can destroy all forms of life, including endospores, are called which of the following? Antiseptics Germicides Sterilants Detergents

Sterilants

What process completely removes or destroys all viable microorganisms, including viruses, from an object or habitat? Sterilization Degermation Disinfection Decontamination

Sterilization

Chemical agents used to control microbes include all of the following except which one? UV light Phenolics Detergents Alcohols Halogens Heavy metals Carbon dioxide Aldehydes

UV light

_____ radiation is most lethal from 240nm to 280nm.

Ultraviolet or UV

Which of the following can cause permanent inactivation of microbial DNA? Formaldehyde Ethylene oxide Ultraviolet rays Gamma rays

Ultraviolet rays Gamma rays

Which of the following can cause permanent inactivation of microbial DNA? Ultraviolet rays Gamma rays Formaldehyde Ethylene oxide

Ultraviolet rays Gamma rays

All of the following describe the typical microbial population targeted by antimicrobial drugs except which of the following? Microbes with variable resistance Complex mixtures of microbes Microbes with variable pathogenic capabilities Uniform populations of like microbes

Uniform populations of like microbes

All of the following describe the typical microbial population targeted by antimicrobial drugs except which of the following? Uniform populations of like microbes Complex mixtures of microbes Microbes with variable resistance Microbes with variable pathogenic capabilities

Uniform populations of like microbes

Which of the following microbial forms are relatively resistant to heat? Fungi Viruses Vegetative cells Endospores

Viruses Endospores

Decontamination methods employ either _____ or physical agents to destroy microorganisms.

chemical

Viruses, prions, and _____ are relatively resistant to heat.

endospores or bacterial endospores

Chemical agents that can destroy all forms of life, including are _____ called sterilants.

endospores or spores

The effect of a germicide is affected by the time of _____.

exposure

The straining of a fluid or air through a membrane to trap microorganisms is known as _____.

filtration or filtering

The bombarding of a substance by waves or particles for diagnosis, therapy, disinfection, or sterilization is referred to as _____.

irradiation

The size of a microbial population is often referred to as the microbial _____.

load

Surfactants typically cause damage to cell _____.

membrane or membranes

Regarding the use of the terms microbicidal and microbistatic, higher temperatures are usually _____, whereas lower temperatures are usually _____.

microbicidal microbistatic

The heat treatment of perishable liquids to destroy heat-sensitive vegetative cells and prevent infection and spoilage is called _____.

pasteurization or pasteurize

Most sterilization is performed using a _____ agent, such as heat.

physical

The inability to _____ even under optimal growth conditions is the practical definition of microbial death.

reproduce, multiply, or replicate

Agents that work by lowering the surface tension of cell membranes are called _____.

surfactants or surfactant

Identify any chemical agent used to control microbes. Detergents UV light Heavy metals Halogens

Detergents Heavy metals Halogens

Which of the following are some of the desirable qualities in a germicide? Solubility in a solvent Narrow-spectrum action Inactivated by organic matter Penetrating ability Broad-spectrum action Rapid action

Solubility in a solvent Penetrating ability Broad-spectrum action Rapid action

_____ radiation is non-ionizing radiation that readily induces mutations.

Ultraviolet or UV