The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is
antisepsis
Scrubbing or immersing the skin in chemicals to reduce the number of microbes on the skin is
Degermation
What would be used to achieve sterility?
Sporicide
The easiest microbial forms to kill or inhibit are
Vegetative bacteria and fungi
The method of removing vegetative microbial life forms and debris to reduce contamination to safe levels is termed
Sanitization
The method of removing vegetative life forms from living surfaces is termed
antisepsis
The removal of all life forms from inanimate objects is termed
sterilization
The alcohol wipe used on a patient's skin before an injection is an example of
Antisepsis
What factors influence the action of microbial agents?
Mode and dosage of the agent, temperature and pH, the type of microorganisms present, the number of microorganisms
Microbial death occurs when there is
no reproduction
Each of the following is a target of antimicrobial agents
Ribosomes, cell wall, cell membranes, cellular proteins
Some microbial control agents are able to ___ cell proteins by breaking bonds that maintain the native state, the three dimensional configuration of the proteins
Denature
Agents that can denature microbial proteins include all of the following except
Moist heat
Alcohol
Acids
Metallic ions
X rays
X rays
Physical agents for controlling microbial growth include all of the following except
Hydrogen peroxide
Pasteurization
Boiling water
UV radiation
Hydrogen peroxide
Sterilization is achieved by
Boiling water
Hot water
Flash pasteurization
Steam autoclave
Steam autoclave
Dry heat
is less efficient than moist heat
The shortest time required to kill or inactivate all the microbes in a sample at a specified temperature is called the
Thermal Death Time (TDT)
The lowest temperature needed to kill or inactivate all microbes in 10 minutes is
Thermal Death Point
Placing organisms at 4 degrees Celsius is
bacteriostatic
Vials of microorganisms that undergo the freeze-drying process, called ____ will remain preserved and viable for years
lyophilization
Removal of moisture by dehydration is called
Desiccation
HEPA filters are used to remove microbes from
air
____ is a control method that removes microorganisms rather than inhibiting or killing them
Filtration
Iodophors include
betadine
___ is a halogen used in gaseous and liquid form for large scale disinfection of drinking water and sewage
chlorine
The chemical agent/s that produce/s highly reactive hydroxyl-free radicals and also decomposes to O2 gas is _______.
Hydrogen peroxide
In lab, inoculating loops are sterilized using ______
incineration
All microbial agents are sterilants
True or false
False
Bacteriostatic agents kill bacterial cells
True or false
False
The goal of antimicrobial therapy is to deliver a drug that will destroy the ____ without harming the ____
Pathogen, host
An ideal antimicrobial drug is ____ rather than ____ and is relatively soluble
microbicidal, microbiostatic
An ideal drug remains potent long enough to act, but does not lead to the development of ____ ______ in microbial populations
Antimicrobial resistance
An effective drug assists the host's ____ and should not cause _____ or other infections
Defenses, allergies
An ideal drug should be readily delivered to the site of ____ in the host, and overall, the drug should be reasonably ____
infection, priced
Gentamicin has a low therapeutic index compared to vancomycin, which has a higher therapeutic index. Which drug has the lowest toxicity?
Vancomycin
Drug A has a TD50 of 25 μg/ml and an ED50 of 21 μg/ml. Drug B has a TD50 of 28 μg/ml and an ED50 of 14 μg/ml. Which drug is the riskier choice?
Drug A
High selective toxicity yields a _______.
high TD50 value and therefore a high TI
State the two correct answers to test your understanding of the primary goals of antimicrobial treatment.
To destroy the infective agent and to be nontoxic to the host and produce no side effects
Choose the method of antimicrobial susceptibility testing that involves measuring and evaluating zones of inhibition around antibiotic disks placed on a culture of bacteria prior to incubation.
Kirby-Bauer Test
The ratio of the toxic dose of an antimicrobial drug (that is toxic to humans) to its minimum therapeutic dose is the _______.
Therapeutic index
The feature of an antimicrobial that allows it to kill or inhibit microbes yet be harmless to the host is referred to as _______.
Selective toxicity
Amphotericin B exhibits a high degree of selective toxicity due to the fact that it targets a structure unique to only fungal cells.
False
It exhibits a low degree since it targets a structure found in all living cells
State the major targets of antimicrobial therapy.
- Cell membrane structure and/or function
- Cell wall synthesis
- DNA/RNA structure and/or function
- Protein synthesis
- Folic acid synthesis
A narrow spectrum antimicrobial would be an appropriate choice to treat an abscess caused by several different microbe species, including both gram-negative and gram-positive bacteria.
False
An antimicrobial drug that is effective against a very diverse array of bacteria is described as _______ spectrum, whereas a drug that is very selective for a just a few different types of bacteria is described as _______ spectrum.
Broad, narrow