Microbiology Quiz 11

1. sterilization of inoculating loop or needle in microbiology labs 2. sterilization and permanent disposal of laboratory waste 3. sterilization of metals, powders, oils

1. bunsen burner 2. furnace incinerator 3.dry oven

1. sterilant for plastics and heat sensitive instruments, prepackaged medical supplies; somewhat toxic; requires a special chamber 2. sterilization of foods such as nuts and spices; breaks down into harmless end-products 3. appropriate for air and surface sterilization; can be used to sterilize rooms and other large spaces

1.Beta Propiolactone 2.Ethylene oxide 3.Chlorine dioxide

1. use of a gaseous or liquid microbicide to destroy microorganisms 2. use of a filter to remove microorganisms from liquids or air 3. use of heat or radiation to destroy microorganisms

1.Chemical agents 2.Mechanical removal 3.Physical agents

1. low temperature sterilizing cabinets for colonoscopies, wound antisepsis, contact lens disinfection 2. chemical sterilant and high level disinfectant; can be used for cold sterilization of instruments that can't withstand heat 3. limited usefulness as a disinfectant because of toxicity, one of the ingredients of embalming fluid

1.Hydrogen peroxide 2.Glutaraldehyde 3.Formalin

1. This process requires use of an autoclave. To sterilize, temperature must reach 121°C for a minimum of 15 minutes. 2.This process requires 3 successive cycles of exposure to free-flowing steam (100°C) alternating with 24-hour incubation periods. This will not kill endospores. 3.This process involves applying heat to beverages to prevent spoilage and kill pathogens. Protocols include holding liquids at 71.6°C for 15 sec. or at 63°C for 30 minutes. This process does not sterilize. This process requires a temperature of 100°C for 30 min. to disinfect but will not sterilize.

1.Steam under pressure 2.Tyndallization 3.Pasteurization 4.Boiling water

1. complete removal or destruction of all microbial forms 2. destruction or removal of vegetative pathogens (but not endospores) from inanimate surfaces 3. destruction of vegetative pathogens on skin and tissue 4. techniques that prevent the entry of microorganisms into sterile tissue 5. cleansing technique that removes microorganisms and debris from inanimate surfaces

1.Sterilization 2.disinfection 3.antiseption 4.aseptic 5.sanitization

1. skin and tissue antisepsis 2.disinfection in dairies, food processing plants, restaurants, hospitals, homes 3.large-scale disinfection of drinking water

1.iodophors 2.hypochlorites 3.chlorine gas

1.antiseptic 2.used in an ointment on 2nd and 3rd degree burns 3.topical germicide on mouth ulcers and root canals 4.incorporated into urinary catheters

1.mercury merthiolate 2.silver sulfadiazine 3.silver nitrate 4.pure silver ions

The following data was obtained when testing the length of time to kill a particular non-spore-forming bacterial species at various temperatures. Identify the thermal death point of this bacterial species.

60ºC

Regarding use of heat to control microbial growth, dry heat is effective at lower temperatures than moist heat.

False

Please choose the answer that best completes the blanks of this sentence in the correct order. __________ radiation causes broad-scale damage to DNA whereas UV light specifically causes formation of __________ dimer formation in DNA.

Ionizing; pyrimidine

What is the primary drawback to using dry heat for sterilization purposes?

It can only be used on very durable objects like glassware or metal surfaces.

Ionizing

Non-ionizing

Please choose the statement that best defines microbial death.

The microorganisms permanently lose the ability to reproduce.

Please choose the statement that identifies the major disadvantage of both cold and desiccation in terms of microbial control.

These methods are bacteriostatic rather than bactericidal.

Cold temperatures will slow the activity of most microbes which may not result in death.

True

A chemical labeled as __________ will inhibit bacterial growth but will not kill them.

bacteriostatic

What bacterial structure is responsible for allowing improperly processed food to cause botulism?

endospores

Please choose the microbial control method that neither inhibits nor kills microbes, but instead physically removes them from liquids or air.

filtration

As microbial load __________, the time it takes for sterilization __________.

increases; increases

What is a common method of preserving bacterial cultures for very long periods of time?

lyophilization

Energy emitted as a result of atomic activity and dispersed at high velocity through matter and space is known as __________.

radiation

Microbial death can best be determined by __________.

the inability to reproduce during optimal conditions

Please choose the answer that best completes the blanks of this sentence in the correct order. The shortest length of time required to kill all test microbes at a specified temperature is the thermal death __________ whereas the lowest temperature required to kill all microbes in a sample within 10 minutes is the thermal death __________.

time; point

Please select the most disadvantageous characteristic of phenolics.

toxicity