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BIOS242, Week 3-OL Name:

Lab 3: Bacterial Isolation Learning Objectives     

Explain the importance of bacterial growth for the investigation of pathological microorganisms Use aseptic techniques Explain the concept of a single colony Perform plate-streaking techniques Use selective media for isolation purposes

Techniques in Lab   

Colony screening Sterile technique Plate streaking

Introduction: Bacterial Isolation Virtual Simulation Lab In the Bacterial Isolation simulation, you will investigate the cause of a contamination of poultry meat by a dangerous bacteria strain that is resistant to common antibiotics. After taking samples from the chicken farm, you will work in the virtual laboratory to isolate single colonies of the deadly bacteria among a variety of different species. To do so, you will learn how to work under sterile conditions, and you will be able to practice and perfect your plate streaking technique. Identifying ampicillin resistant bacteria The premise of the Bacterial Isolation lab is a report of ampicillin resistant bacteria in poultry meat. You will visit the place of origination, a chicken farm, in hopes of identifying the bacteria strain. The first task is to take a sample, which will contain a variety of bacterial strains, and from that, you must identify which strains are resistant to ampicillin by isolating single colonies. Aseptic technique In the Bacterial Isolation lab, you will learn how to use aseptic techniques—for example, remembering to turn on the Bunsen burner and sterile their loop in between streaks. Plate streaking technique In order to identify the specific bacteria strain, you will have to perform bacterial isolation using the plate streaking technique. There is an unlimited supply of agar plates, giving you the opportunity to practice this technique as many times as you like. Results are given immediately, as opposed to waiting a full 24 hours for incubation, as when performed in real life as opposed to in a virtual simulation. You will also streak a special Salmonella Shigella agar. The Salmonella 1

BIOS242, Week 3-OL Name:

Shigella agar contains a certain medium that only promotes growth of Gram-negative strains. Each of the different strains will exhibit a certain phenotype when grown on the Salmonella Shigella agar. By using this information you can identify the specific strain that is resistant to ampicillin. The sample will then be sent for further analysis to fully confirm the identity. Will you be able to complete the task with your knowledge on bacterial isolation and successfully isolate the dangerous bacterial strain? Questions: 1. Purpose: Please describe in complete sentences and in your own words, the purpose of this experiment. The purpose of the lab was to learn about the culturing of bacteria and learn how to isolate it and test it and learning how to perform a plate steak technique.

2. Why is proper aseptic technique important in microbiology? Aseptic technique is important in microbiology because it provides a barrier between the microorganisms in the environment and the sterile cell culture.

3. What is the importance of flaming the inoculating loop or needle before and after each inoculation? The inoculating loop is flamed to avoid contamination. Due to the fact that there are bacteria everywhere, it is important to keep all equipment sterile. If not, the contaminating bacteria from the lab room might overgrow the agar plate

4. If you do not wait 10 – 20 seconds after flame sterilizing the inoculating instruments before obtaining the sample, what might be the consequences?

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If you do not wait for the proper time after flame sterilization, it could still be hot, and this will kill the bacteria during the second it is stuck into the culture causing the experiment to be impossible or incorrect.

5. Why is it important to flame neck of the tubes immediately after uncapping and before recapping the tubes? It is important to flame the neck of the tube to maintain sterility. This will prevent transfer of bacteria into the new specimen and prevent outside bacteria from also getting into the specimen.

6. Reflection: Write 5 sentences on what you learned from this simulation, what did you like and what was something that you would not prefer to be in the simulation.

I learned salmonella infections are caused by contaminated foods. Foods such as meet, or chicken have to be properly cooked to prevent salmonella infection. If a meat or chicken contains antibiotic-resistant Salmonella, it makes it more complicated to treat. Bacteria grow much slower when kept in the fridge. Flames kill microorganisms that float in the air, so one should turn on the Brunson burner in the lab.

I really liked that I was able to learn how to actually preform an experiment trying to isolate a colony. When I did it in correctly the first time, the labster allowed me to redo it and eventually I did it the proper way. The one thing that I dislike about the experiment is that sometimes the labster would freeze and I would have to wait for it

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to unfreeze. It takes a lot of time to complete the assignment due to the program being very slow.

Grading Rubric: Activity Document Submission

Total

Deliverable Complete lab report and answer questions



Purpose (2 point)

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Questions (8 points)



Reflection (5 points)

Complete all lab

Points 15

15

4...