Quiz On Temp And Growth And Kirby Bauer Flashcards
What are antibiotics
Natural antimicrobial agents produced by microorganisms
What are antimicrobials or antimicrobics?
All substances used to treat bacterial infections
Minimum inhibitory concentration or mic
The junction where the concentration of antimicrobic has become too low to effectively stop growth
Where the zone of inhibition ends
What is a zone of inhibition?
A clear zone where the bacteria will not grow because of antimicrobial agents
Difference between bactericidal and bacteriostatic drugs
Bactericidal kill the organism
Bacteriostatic stop the bacteria from dividing but do not kill them
What is the depth on a Mueller Hinton agar and why is it important?
4 mm in either 150 mm or 100 mm petri dish
It is important because of its effect upon the diffusion
The Thick agar slows lateral diffusion and thus produces smaller zonesl
What is inoculation made with in a Kirby Bauer method? And how long is it incubated for?
Incubation is made with a broth culture
It is generally incubated 4 to 6 hours to bring it to the exponential phase
In the exponential phase, what is the broth culture diluted to match?
A .5 McFarland turbidity standard
What is the resistance break point in the Kirby Bauer method?
The zone diameter below which all resistant strains fall
What is the susceptibility break point in the Kirby Bauer method?
The zone diameter above which all resistant strains fall
Two most common bacteria used in the Kirby Bauer method
E. Coli
S. Aureus
What are the antibiotics typically used in the Kirby Bauer method?
Penicillin chlorophenical tetracycline trimethoprim streptomycin ciprofloxacin
What is a cardinal temperature?
Every bacteria species is characterized by a minimum maximum and optimum temperature
Collectively known as its Cardinal temperature
What is the optimum temperature
The temperature at which an organism grows the fastest
What is a psychrophile
Organisms that only grow below 20° c
Common in the ocean Arctic and Antarctic habitats
What is a psychrotroph?
Bacteria adapted to cold habitats that fluctuate from about 0° c. To about 30° c
What are mesophiles?
Bacteria adapted temperatures between 15° c and 45° c
Most bacteria that reside in the human body as well as numerous human pathogens are mesophiles
What are thermophiles
Organisms adapted to temperatures above 40° c
What are obligate thermophiles?
Organisms that will not grow at temperatures below 40° c
What are facultative thermophiles?
Bacteria that will grow below 40° c but prefer above
Environments where thermophiles are found
Composting organic material
Soil surfaces subjected to direct sunlight
Silage
What are extreme thermophiles and where are they found
Bacteria and archae isolated on hydrothermal vents and other geothermal sites
They can survive temperatures in the 65° c and 110° c range
What is the optimum temperature for extreme thermophiles
80° c
What temperature can methanopyrus survive up to?
122° c
What does TSB or TSA stand for
Tsb is triptych soy broth
TSA is tryptic soy agar plates
