Microbiology Ch. 11

What is the minimum temperature to sterilize with the autoclave

121 degrees C

What is the minimum PSI to sterilize with the autoclave?

15 PSI

What is the minimum time to sterilize with that autoclave

15 minutes

What 6 factors influence the action of antimicrobial agents

Number of microbes Nature of microbes in the population Temperature and pH of environment Concentration or dosage of agent Mode of action of the agent Presence of solvents, organic matter, or inhibitors

heat is applied to kill potential agents of infection and spoilage without destroying the food flavor or value 63°C-66°C for 30 minutes (batch method) 71.6°C for 15 seconds (flash method) Not sterilization - kills non-spore-forming pathogens and lowers overall microbe count; does not kill endospores or many nonpathogenic microbes

Pasteurization

intermittent sterilization for substances that cannot withstand autoclaving Items exposed to free-flowing steam for 30-60 minutes, incubated for 23-24 hours and then subjected to steam again Repeat cycle for 3 days Used for some canned foods and laboratory media Disinfectant

Tyndallization

The use of physical or chemical process to destroy vegetative pathogens on inanimate objects is: a. disinfection b. sterilization c. antisepsis d. sanitization e. degermation

a. disinfection

Silver sulfadiazine is used a. in antisepsis of burns b. as a mouthwash c. used to treat genital gonorrhea d. to disinfect water

a. in antisepsis of burns

Dry heat: a. is less efficient than moist heat b. cannot sterilize c. includes tyndallization d. is used in devices called autoclaves e. will sterilize at 121 C for 15 minutes

a. is less efficient than moist heat

Disinfection of beverages, such as apple juice, milk and wine is optimally achieved by: a. pasteurization b. chlorination c. moist heat autoclave d. filtration e. boiling water

a. pasteurization

Sanitation is a process by which a. the microbial load on objects is reduced b. objects are made sterile with chemicals c. utensils are scrubbed d. skin is debrided

a. the microbial load on objects is reduced

Microbilogical contaminants are best described as: a. unwanted microbes present on or in a substance b. any and all microbes present in or on a substance c. pathogenic microbes present in or on a substance d. vegetative microbes present on or in a substance e. none of these

a. unwanted microbes present on or in a substance

What is the use of chemical agents directly on exposed body surfaces?

antisepsis

The temperature pressure combination for an autoclave is a. 100C and 4 PSI b. 121 C and 15 PSI c. 131 C and 9 PSI d. 115 C and 3 PSI

b. 121 C and 15 PSI

Any process that destroys the non-spore forming contaminants on inanimate objects is a. antisepsis b. disinfection c. sterilization d. degermation

b. disinfection

High temperatures _____ and low temperatures _____ a. sterilize, disinfect b. kill cells, inhibit cell growth c. denature proteins, burst cells d. speed up metabolism, slow down metabolism

b. kill cells, inhibit cell growth

Detergents are a. high-level germicides b. low-level germicides c. excellent antiseptics d. used in disinfecting surgical instruments

b. low-level germicides

The primary mode of action on non-ionizing radiation is to a. produce superoxide ions b. make pyrimidine dimers c. denature proteins d. break disulfide bonds

b. make pyrimidine dimers

The process that destroys or removes all microorganisms and microbial forms including bacterial endospores is: a. disinfection b. sterilization c. antisepsis d. sanitation e. degermation

b. sterilization

The easiest microbial forms to kill or inhibit are a. naked viruses b. vegetative bacteria and fungi c. endospores d. protozoan cysts e. mycobacterium and Staphylococcus

b. vegetative bacteria and fungi

What 5 microbial forms have the least resistance to physical and chemical controls?

bacterial vegetative cells fungal spores enveloped viruses yeast protozoan trophozoites

An agent that kills bacteria

bacteriocidal

Any process or agent that inhibits bacterial growth

bacteriostatic

An example of an agent that lowers the surface tension of cells is a. phenol b. chlorine c. alcohol d. formalin

c. alcohol

The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is: a. disinfection b. sterilization c. antisepsis d. sanitation e. degermation

c. antisepsis

Ionizing radiation removes _____ from atoms a. protons b. waves c. electrons d. ions

c. electrons

Microbial control methods that kill _____ are able to sterilize a. viruses b. the tubercle bacillus c. endospores d. cysts

c. endospores

Which of the following is an approved sterilant a. chlorhexidine b. betadyne c. ethylene oxide d. ethyl alcohol

c. ethylene oxide

_____ is the iodine antiseptic of choice for wound treatment a. 8% tincture b. 5% aqueous c. iodophor d. potassium iodine solution

c. iodophor

Microbe(s) that is/are the target(s) of pasteurization include(s) a. Clostridium botulinum b. Mycobacterium species c. Salmonella species d. both b and c

d. both b and c

A microbicidal agent has what effect a. sterilizes b. inhibits microorganisms c. is toxic to human cells d. destroys microorganisms

d. destroys microorganisms

The most versatile method of sterilizing heat-sensitive liquids is a. UV radiation b. exposure to ozone c. beta propiolactione d. filtration

d. filtration

A chemical with sporadical properties is a. phenol b. alcohol c. quaternary ammonium compound d. glutaraldehyde

d. glutaraldehyde

The primary action of _____ heat is to _____ a. dry, destroy cell walls b. moist, kill vegetative cells c. dry, dissolve lipids d. moist, denature proteins

d. moist, denature proteins

What is scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin?

degermation

The loss of normal characteristics resulting from some molecular alteration like heat/chemicals on proteins

denaturation

What is the process that destroys all vegetative pathogenic organisms on a surface?

disinfection

Endospores can be killed by: a. dry heat at 170 C for 2 hours b. incineration c. glutaldehyde for 3 hours d. ethlyene oxide for 3 hours or more e. all of these choices are correct

e. all of these

Which of the following items are typically irradiated in order to kill microbes a. ground beef and other meat and poultry b. human tissues such as heart valves and skin c. operating room air d. surgical gloves e. all of these

e. all of these

What gas is used to sterilization?

ethylene oxide

true/false Bacteriocidal agents are sterilants

false

What is the mechanical removal method that controls microbial growth?

filtration

What products are irradiated to kill microbes

food

A chemical that can kill fungal spores, hyphae, and yeast

fungicidal

What are two types of chemical agents that control microbial growth?

gasses liquids

What are 2 types of physical agents that control microbial growth?

heat radiation

What are two examples of sepsis?

infected wounds blood infections

What radiation is used to eject electrons from atoms in cells

ionizing radiation

The separation of a dissolved solid from the solvent by freezing the solution and evacuating the solvent under a vacuum; freeze drying

lyophilization

Microbes present at a given place and time that are undesirable or unwanted

microbial contaminants

Which is more effective at killing organisms, dry or moist heat?

moist unless incineration is used

What radiation is used to form pyrimidine dimers in DNA

non-ionizing radiation (UV radiation?)

What are the 3 types of agents that control microbial growth?

physical agents mechanical removal methods chemical agents

What two microbial forms have the highest resistance to physical and chemical controls?

prions bacterial endospores (bacillus, clostridium)

What is the function of HEPA filters

provides a flow of sterile air to hospital and sterile rooms

The growth of microorganisms in the tissues

sepsis

A chemical agent capable of destroying bacterial endospores

sporicidal

What is the process that destroys all microorganisms?

sterilization

Chemicals that work as microbicidal agents by lowering surface tension of cell membranes of lipids. "opens up" the membrane to create leaky spots for chemicals to enter the cell

surfactants

The lowest temperature that achieves sterilization in a given quantity of broth culture upon a 10 minute exposure

thermal death point

The least time required to kill all cells of a culture at a specified temperature

thermal death time

A chemical agent that inactivates viruses, especially on living tissue

virucidal