Microbiology Is Cool

Misc. (kinda just random lol)

100

What is the countable range?

30-300 CFU

200

A 1 gram soil sample was added into 99 ml of sterile water (labeled as tube A). Subsequently, 1 ml of tube A was transferred to 9 ml of sterile water (labeled as tube B), and tube B was serially diluted 4 additional times (final dilution labeled as tube F). What is the total dilution of tube F?

10^-7

300

What is the EPA's safe drinking water standard for Enterococcus spp.?

<1 CFU/100 ml

400

True or False: Gram positive bacteria are more resistant to antibiotics than Gram negative due to the presence of a thick peptidoglycan layer.

False

500

How does streptomycin kill bacterial cells?

Frame shift mutations lead to the synthesis of faulty proteins

Biochemical

100

You are given a test tube with a bright pink solution containing ammonia and CO₂, what amino acid was in the tube previously and what enzyme broke it down?  

Urea, urease

200

Black precipitate in SIM agar indicates your bacterium expresses ______.  

cysteine desulfhydrase

300

Phenylalanine is broken down into H2O, ______, & _______ by phenylalanine deaminase.

phenylpyruvic acid, NH³  

400

In DC and LDC broth a positive result should be have a _____ LDC tube and _____ DC tube. In the LDC tube, the presence of _____ raises the pH and indicates expression of ____.

purple, yellow, cadaverine, lysine decarboxylase

500

An unknown bacterium was inoculated in nitrate broth and incubated for 48 hours at 35˚C. No gas was observed in the Durham tube, but fizzing was observed after the addition of sulfamic acid. What enzyme was produced by this bacterium?

Nitrate reductase

Media

100

True or False: Mannitol-salt agar, Blood agar, and Mitis-Salivarius agar are selective and differential

False

200

LST-MUG detects ____ and ____.

fecal coliforms AND coliforms

300

Mannitol-Salts Agar contains what 2 differential ingredients?

mannitol and phenol red  

400

Sodium azide inhibits ______ and used in _______ agar.  

cytochrome c oxidase , KF-Strep  

500

Methylene blue is ______for ______ bacteria and is a component of _____ agar.  

selective, gram negative, eosin methylene blue  

Organism Identification

100

True or False: S. salivarius colonies appear blue and produce capsules on mitis-salvarius agar.  

True

200

True or False: Turbidity, gas, and fluorescence in LST-MUG broth and growth on EMB agar means your sample is positive for E. coli.  

False

300

You streak a Mannitol-salt agar plate and after incubation you see growth and the agar around the growth has turned yellow. What bacteria was         inoculated?

Staphylococcus aureus  

400

You inoculate LST MUG broth and after incubation you see growth and gas. What colors would you expect to see if you did a Gram and endospore stain on the bacterium from this LST-MUG broth?

Pink and pink

500

You are given a bacterium that is gram positive and catalase negative. You streak a mitis-salvarius plate. After incubation, there are small, flat, black bacteria on the mitis salvarius agar. What bacteria were you given?  

Enterococcus