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 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.
2. Why is proper aseptic technique important in microbiology?
3. What is the importance of flaming the inoculating loop or needle before and after each inoculation?
4. If you do not wait 10 – 20 seconds after flame sterilizing the inoculating instruments before obtaining the sample, what might be the consequences?
5. Why is it important to flame neck of the tubes immediately after uncapping and before recapping the tubes?
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.
3. Flaming the inoculating loop or needle before and after each inoculation is important because it destroys any contaminant that may be present on the surface that could interfere with the sample being tested or cause an infection if entered into an open wound. This procedure also helps to ensure that only sterile materials are used for testing purposes, thus yielding accurate results free from external sources of error caused by contaminants such as dust particles or microbes carried over from previous tests or experiments.
4. If you do not wait 10 – 20 seconds after flame sterilizing the inoculating instruments before obtaining the sample, there is a greater chance for external sources of error due to possible residual heat transfer which can reduce accuracy in results due to differences in temperature affecting reaction rates along with potential introduction of contaminants such as dust particles into your culture media that could lead to false positives during analysis and identification efforts performed later on down stream processes stages after analysis has been completed within a lab environment..
5. It is important to flame neck of tubes immediately after uncapping and before recapping them because this further reduces any possibility for cross-contamination between cultures due to airborne matter settling inside open tubes while they are not capped off properly without proper sealing conditions established at all times while performing laboratory procedures as well as helping reducing chances for human errors leading up towards result mistakes associated with inaccurate data gathering processes when using laboratory equipment such as test tubes etc...
6 Reflection: I learned about how important proper preparation and sterility protocols are when working in a laboratory setting involving microbes through this simulation lab project; I liked how easy it was understand steps required during streak plating process thanks to visuals provided throughout my experience; something I did not prefer was time required between streaks since it felt like too much waiting around virtual lab bench area; overall exercise gave me insight what happens behind scenes when conducting bacteriological work which made me appreciate nature involved far more than before; also became aware importance following safety rules under all circumstances especially those related working environments where hazardous bacteria exist like poultry farms here explored via virtual world created by game developers; finally despite lack personal interaction compared physical labs I was able enjoy digitalized version where no real danger posed upon user yet still having opportunity learn how isolate dangerous strains out general population among mixed culture presented us first step challenge ahead undertaken course our expedition exploring depths unknown land filled microbiological life previously untapped realm anyone outside field study until now!