The following data were obtained from a disk-diffusion test. Antibiotic Zone of Inhibition 15 mm 0 mm 7 mm 15 mm a. Which antibiotic was most effective against the bacteria being tested? b. Which antibiotic would you recommend for treating a disease caused by this bacterium? c. Was antibiotic A bactericidal or bacteriostatic? How can you tell?

You make a smear of E. coli and then simple stain the slide with methylene blue. If you failed to use correct aseptic technique by not sterilizing the loop before picking up the bacterial sample for the smear, what results may be seen under the microscope?   A Both blue and purple cells may be seen on the slide. B No cells may be visible on the slide. C There may be cells of different shapes, sizes, and arrangements.

Match the confirmation test to the category of bacteria. (each category can be used multiple times)  Categories: -Gram Positive  - Gram Negative  Tests: Match with category  A. Citrate test is category.... B. Indole test is category...  C. Raffinose test is category... D. Catalase test is category....

An inoculating loop must be flamed to uniform orange-hot from base to tip   A. after culture is transferred to the wire loop but before transfer to new media   B. before culture is transferred to the wire loop and after culture is transferred from the wire loop to new media   C. after culture is transferred to the wire loop and before culture is transferred from the wire loop to new media   D. before culture is transferred to the wire loop

What is the independent variable? What is the dependent variable? Suggest a control for this experiment?

E-strip testing can be used to determine a drug MIC against an organism. Which ONE of the following is correct? Select one: A. The zone of inhibition is inversely proportional to the activity of the drug B.   The E-strip result guides to the maximum drug concentration that can be used to clear an infection   C. The E-strip is impregnated with a fixed concentration of drug D. The E-strip is used broadly clinically to determine if an organism is resistant to a drug E.   The MIC is read where bacterial growth touches the E-strip

At the station there is a 2 mL microcentrifuge tube containing sheep blood and 3 tubes containing the following solutions: 0 mM, 300 mM, 600 mM of sucrose. The tubes are randomly labelled A, B, C.  2 mL of each solution were transferred to a different microcentrifuge tube, 20 ul of blood were then added to each tube, and they were mixed well by inverting the tube for multiple times.  They were observed and it was determined whether the solution in each tube was hypotonic (Yes or No) relative to the blood cells. In addition, the solutions were diluted with water to help you determine which solution is which sucrose concentration. What sucrose concentration corresponds with each tube?   Tube Hypotonic (Yes/No) Hypotonic after 1:1 dilution with water (Yes/No) Most likely Sucrose concentration (mM) A No Yes   B Yes Yes   C No No

a. Identify the cell shape, cell arrangement, and Gram reaction of the Unknown microbe in the image below. b. Suppose the corresponding Gram negative control were purple. Explain what step(s) of the Gram stain you would adjust and how you would adjust them to ensure the accuracy of your Unknown results

You do a viral plaque assay using the six well plate shown below. The dilution scheme, what was infected on each well, and the results of the plaque assay are shown below. What is the viral titer of the original lysate?  A. ~1.1 *10^6 PFU/mL   B. ~1 *10^7 PFU/mL   C. ~3 * 10^7 PFU/mL   D. ~2 * 10^6 PFU/mL   E. ~3.5 *10^6 PFU/mL   F. ~1.1 * 10^5 PFU/mL   G. ~3.5 *10^5 PFU/mL

After an antimicrobial drugs test, the following results were obtained from a disk-diffusion test against a bacterium.   Antiboitic A= 6mm Antibiotic B= 18mm Antibiotic C= 11mm Antibiotic D= 19mm which drug should be used to treat an infect caused by this bacterium (assuming everything else is equal about these antibiotics)?