Lab 11 Assessment Antimicrobial Susceptibility Test on Unknown Bacterium
Lab 11 Assessment
Antimicrobial Susceptibility Test on Unknown Bacterium
1. Click on this link, and read up on the theory behind and the protocol for performing a Kirby Bauer Antibiotic Sensitivity Assay https://bio.libretexts.org/Learning_Objects/Laboratory_Experiments/Microbiology_Labs/Microbiology_Labs_/09%3A_Kirby-Bauer_(Antibiotic_Sensitivity)
2. Review the given antibiotic sensitivity results for each of your unknowns. Please understand that I could not find all identical assays, performed with the same antibiotics.
3. Your assignment this week is to:
a. Finish your results section, with the antibiotic sensitivity results from this week included
i.understand that some of these results are in diameter of zone of inhibition (in mm), some report S = susceptible or NS = not susceptible, some report % resist, and others a photo of the zones of inhibition
ii. The goal here is not to have perfect results but, rather, to help support what you know about if your unknown is gram positive or gram-negative, and how its biochemical characteristics from the past couple week’s tests.
For example, if you have Unknown C/3, you know it is Gram-negative; therefore, would you expect it to be susceptible to penicillin? Why or why not?
b. Write at least the first two paragraphs of your Discussion and Conclusion Section
i.Remember, in your Results section, you are simply stating WHAT you observed.
1. For example, you may have a photo of your bacterium growing on MSA and the figure legend will read, “Figure X. Growth of Unknown A on mannitol salt agar (MSA).
And your description of your results would describe what you observed (e.g. Unknown A exhibited ample growth on MSA with colonies pink in colony.)
ii. For the Discussion and Conclusions, this is where you say when the results MEAN or imply. For example, “Based on the fact that Unknown A exhibited ample growth on MSA, it appears that this bacterium is halotolerant, and can survive in high salt conditions.
In combination with the cocci morphology and the fact that this bacterium is gram-positive, this strongly suggests that Unknown A is a Staphylococcus species. Then, based on the lack of color change of the MSA from pink to yellow implies that Unknown A is….”