What is chemically defined and give an example.
What is complex media and give an example.
What is enriched media and give an example.
Why is it necessary for growing fastidious bacteria?
What is the relationship between the amount of bacteria in a culture and the absorbance?
What is the relationship between the amount of bacteria in a culture and the transmittance?
Would heterotrophic organisms grow well in inorganic salt media? Why or why not?
Why is complex media generally used to cultivate microorganisms?
Describe the minimum, optimal and maximum growth temperatures.
Differentiate between aerobes, anaerobes, facultatives and microaerophiles
obligate aerobes-have the ability to live in oxygen and require oxygen for metabolism
obligate anaerobes-are not able to live in oxygen and do not require oxygen for metabolism
facultative-have to preference, growth is seen in both aerobic and anaerobic environments
microaerophiles-can grow in oxygen, but only require a small amount for metabolism
Describe how the anaerobic chamber achieves an anaerobic environment.
Describe the indicator that an anaerobic environment is present
What is fermentation?
What is being distinguished in the carbohydrate fermentation test?
What is the indicator used in the carbohydrate fermentation test?
What is the appearance of a positive result for a carbohydrate fermentation to an acid? To a gas?
What is the appearance of a negative result for carbohydrate fermentation to an acid? To a gas?
What is being distinguished in the MR and VP test?
What reagents are used in the MR and VP test?
What is the appearance of a negative result for the MR and VP tests
Explain why you would expect no growth on the LB/amp/-DNA plate
Explain why you would expect isolated colonies to grow on the LB/amp/+DNA plate.
Explain the purpose of the arabinose on the LB/amp/ara/+DNA plate
Arabinose is a sugar that acts as an inducer to the gfp gene. When arabinose is present it removes the inhibitor from the section of the plasmid containing the gfp gene and allows transcription and translation to take place. The gfp gene produces the green fluorescent protein and causes colonies of bacteria to have a green fluorescent glow when exposed to UV light
Explain why you would expect a lawn of growth on the LB/-DNA plate
What is selective media?
What is differential media?
Starch hydrolysis (amylase)
SIM: Hydrogen Sulfide (Sulfur)
-Tests for the ability of the bacteria to utilize the citrate in the media as the sole source of carbon with the citrase enzyme.
-Bacteria that do this then use the ammonium hydroxide and ammonium phosphate as a sole source of nitrogen. When they break down the ammonium phosphate and ammonium hydroxide, they release ammonia. This raises the pH to produce a basic environment.
-Bromthymol blue in the medium is the indicator which will turn Prussian blue (KU blue) when it is basic and yellow when it is acidic. So a positive result for Citrate Utilization = Prussian blue (KU blue) color. A Negative result for Citrate Utilization = forest green color (no change in the color)
Define transient microbiota
Define normal microbiota
Name 4 locations where normal microbiota is present on the host
Describe the ecological relationship between most normal microbiota and the host
Explain how normal microbiota can sometimes be an opportunistic pathogen
Use "shapes" to describe a colony on a plate:
Use "elevation" to describe a colony on a plate
Use "margin" to describe a colony on a plate
What are the factors that affect the efficiency of the disinfectants and antiseptics?
What does the zone of inhibition indicate about the bacteria's relationship to the chemical?
a chemical produced by certain species of bacteria and fungi for the purpose of competing better with their competition. The term traditionally refers to the naturally acquired chemotherapeutic agents. However, so many of the naturally occurring antibiotics have been chemically changed in the laboratory that most of the antibiotics are truly “semi-synthetic” and not true antibiotics
What is the minimum inhibitory concentration (MIC) and how is it determined?
-the most dilute concentration of antibiotics that are still able to kill microbes.
-Two methods are used – the MIC test uses several tubes of serially diluted antibiotics (1:2, 1:4, 1:8, etc…), the same concentration/amount of bacteria is added to each tube and incubated. The MIC is then determined by looking at the most dilute solution that is still effective against the bacteria (no growth in the tube).
-The second method is the E-Test in which strips with increasing dilutions of the antibiotic on the back side of the strip are placed on an inoculated plate. Wherever the zone of inhibition crosses the strip, that indicates the MIC.
What conditions must be controlled to make the MIC test repeatable and accurate?
What are the modes of action for the antibiotics used in our lab.
Name the 5 genera of Enterobacteriaciae bacteria tested for in this unknown lab.
Why are biochemical tests required to identify bacteria?
Why are biochemical tests required to identify the genus of these bacteria?
How are fermentation tests used to identify bacteria?
What are the five I’s of the microbiology lab and how were they used in this lab?
Why is it better to have and Enzyme-linked antibody rather than Substrate-linked antibodies in this test?
Why should the secondary antibody stick to the primary antibody in an indirect ELISA test?
Why is it necessary to switch tips or pipettes when removing serum from the wells of different rows (between patients’ serum or between different dilutions).
Why is it necessary to wash between each step?
What is the Bactistaph test testing for to identify Staph bacteria?
What type of diagnostic test is the Group A Strep Test?