chapter 9Which statement MOST accurately describes the microbial death rate after cells are exposed to a microbicidal agent?

Pasteurization is used in

Milks and juices

Example of disinfection

Phenolics, alcohols, aldehydes, soaps

Oxidizing agents are particularly effective against Fill in the blank organisms.

anaerobic

Damage to proteins and nucleic acids

-Protein function depends on 3-D shape -Extreme heat or certain chemicals denature proteins -Chemicals, radiation, and heat can alter or destroy nucleic acids -Produce fatal mutants -Halt protein synthesis through action on RNA

Factors affecting the efficacy of antimicrobial methods

-site to be treated - harsh chemicals and extreme heat cannot be used on humans, animals, and fragile objects -method of microbial control based on site of medical procedure

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

With the Fill in the blank test, swabs are taken from actual objects before and after the application of disinfectants and antiseptics.

in use test

Common methods of using moist heat to control microbial growth include all of the following EXCEPT Fill in the blank.

incineration

Surfactants function as microbicide agents because they Fill in the blank.

lower the surface tension of solvents

A phenol coefficient greater than 1 indicates that an agent is Fill in the blank.

more effective than phenol

Which of the following disinfectants acts against cell membranes?

phenol

Which class of surfactant is most soluble in water?

quaternary ammonium compounds

Ending - stasis/static

Inhibition but not complete destruction of a type of microbe

2 examples of antisepsis

Iodine and alcohol

The Fill in the blank test was approved by the European Union to determine the capacity of a chemical to inhibit bacterial growth.

Kelsey-Sykes capacity

thermal death time

shortest length of time required to kill all test microbes at a specified temperature

Why is a solution of 70% to 90% alcohol more effective at denaturing proteins than 100% alcohol?

Water is required to denature proteins.

formalin

the aqueous solution of formaldehyde gas; the most commonly used tissue fixative

Biosafety Level 3 includes .

double sets of entry doors

Ideally agents should be

1. Inexpensive 2. Fast-acting 3. Stable during storage 4. Capable of controlling microbial growth while being harmless to humans, animals, and objects

A particular sterilization process takes 25 minutes to kill all organisms in a sample containing 100,000 microbes. How long does it to eliminate 90% of the organisms using this process?

5 minutes

In degerming what role do chemicals play in the removal of microbes

A secondary role

The endospores of which organism can be used as a biological indicator of sterilization?

Bacillus stearothermophilus

What is the first thing you should do to control microbial growth on a surgical instrument that is covered with blood?

Clean the blood off the instrument, then proceed to sterilize it.

Antiseptics are similar to:

Disinfection, they are the same except this is at a lower strength so it doesn't harm living tissue

Which of the following procedures should be used to sterilize a solution containing a heat-sensitive protein?

Filtration

Which statement MOST accurately describes the microbial death rate after cells are exposed to a microbicidal agent?

Microbicidal agents kill a constant percentage of cells over time.

decimal reduction time

Minutes to kill 90% of a population at a given temperature

Antisepsis reduce...

Number of microorganisms and viruses, particularly potential pathogens ON LIVING TISSUE

degerming (degermination) is

Removal of microbes by mechanical means (hand washing, alcohol, swabbing at cite of injection)

Sanitation is

Removal of pathogens from object to meet public standards

glutaraldehyde

Solution used for high-level disinfection and sterilization

Disinfection is

The destruction of most microbes, viruses, and particularly pathogens on NONLIVING TISSUE

Aseptic is

The environment or procedures free of pathogenic contaminants. Usually used for prep for surgical field. Scientists and healthcare workers follow this

Why is the heat treatment brief in pasteurization?

To minimize alteration of taste and nutrients in the food or beverage... microbes are still present and can cause spoilage

Pasteurization

Use of heat to destroy pathogens and reduce the amount of spoilage microorganisms in foods and beverages

Boiling water for 10 minutes is effective in ridding it of

both growing bacteria and enveloped viruses.

What is another name for the intermediate-level disinfectant compound phenol?

carbolic acid

Alteration of cell walls and membranes

cell wall maintains integrity of cell, cells burst due to osmotic effects when damaged; cytoplasmic membrane contains cytoplasm and controls passage of chemicals into and out of cell, cellular contents leak out when damaged; nonenveloped viruses have greater tolerance of harsh conditions

A chemical agent that dissolves lipids can damage

cells and enveloped viruses

quaternary ammonium compounds

commonly known as quats; are products made of quaternary ammonium cations and are designed for disinfection on nonporous surfaces. They are appropriate for use in non-critical (non-invasive) environments and are effective against most pathogens of concern in the salon environment

ethylene oxide

gas used to sterilize surgical instruments and other supplies

The ending CIDE/ CIDAL

destruction of a type of microbe

Which antimicrobial chemical has been used to sterilize spacecraft?

ethylene oxide

Which of the following chemicals is active against bacterial endospores?

ethylene oxide

A scientist develops a new medication that is a protein compound and that must be administered by injection. Which of the following would be the most effective and safest means of preparing a sterile solution of the new medication?

filtration

thermal death point

the lowest temperature required to kill all microbes in a sample in 10 minutes

Which of the following disinfectants contains alcohol?

tincture of bromine

The current standard test in the U.S. for measuring efficacy of disinfectants and antiseptics is the Fill in the blank test.

use dilution