Bacteria are the leading cause of diseases. In clinical settings, part of diagnosing illnesses are lab tests meant to identify unknown bacteria. This is important so doctors can figure out the right treatments for patients suffering from bacterial infections. Knowing what species of bacteria have infected patients also guides doctors in prescribing the appropriate antibiotics. Thanks to these treatments, diseases that were deadly in the past are now easily curable.
For students looking to pursue medical degrees, this topic is important. But students learning about it for the first time might find the lessons intimidating. Thankfully, there are many ways to make it more engaging and approachable. Read on to find out how.
Image from Labster's virtual lab: Identification of Unknown Bacteria: Help save baby Kuppelfangs from an epidemic.
First, let’s look at why students find it challenging to learn how to identify unknown bacteria. Here are the top three challenges according to both students and teachers.
Bacteria are tiny, single-celled organisms, and students need to use microscopes to see them. Even under the microscope, different species of bacteria can still be hard to distinguish. To effectively identify bacteria, different tests, staining, and culture media need to be used.
Identifying unknown bacteria involves a battery of tests, including catalase tests, oxidase tests, differential media, staining, and more. Each test has a different set of methods to follow. The entire identification process may end up confusing for many students.
Unknown bacteria may or may not cause disease. Thus, the safest way for students is to assume they are handling a pathogenic (disease-causing) species of bacteria. Adequate precautions must be taken to avoid being infected. However, for students not well-versed in safe techniques in working with bacteria, they may become anxious or afraid of performing bacterial identification tests.
Based on the difficulties students have in identification of unknown bacteria, here are five tips for educators to make the topic more interesting. Each piece of advice addresses a particular challenge that students face.
Identification of unknown bacteria may be a difficult topic on its own for many students. But if you talk about how this topic can help people, students will start to open up more. Here are a few points to consider.
Identifying unknown bacteria can help many sick people recover from their illness. Cases of food poisoning, for example, have been linked to a species of bacteria known as E. coli. If a doctor suspects food poisoning in his patient, he may order a lab test that includes bacterial identification. If E. coli comes up in the lab result, the doctor can prescribe the proper antibiotics and treatments to minimize the effects of food poisoning on the patient.
Another example is the eradication of otherwise deadly diseases, like the bubonic plague. In the mid-1300s, millions of lives in Europe were claimed by this disease. It was even called the Black Death because of how fatal it was to so many people. But now, thanks to antibiotics and techniques to identify bacteria, bubonic plague is a curable illness. Scientists have identified the cause of this disease – a species of bacteria called Y. pestis. Antibiotics are able to destroy the bacteria, saving the lives of people who have this illness.
Identifying unknown bacteria is also helpful in determining if water sources are safe. Scientists use similar tests to find out how much bacteria is in a body of water, like lakes, rivers, and oceans. If an unusually high number of certain species of bacteria are detected, people will be advised to avoid that water source to prevent illness.
If students can appreciate these applications of identifying unknown bacteria, they will sooner realize how valuable this topic is.
Students will learn this topic better if they are exposed to visual aids. These include illustrations, diagrams, graphics, and images of different bacteria and the techniques used to identify them. Bacteria are tiny organisms, so it will help students to see them up close through microscope images. Also, the processes involved in identifying unknown bacteria are easier to understand when diagrams guide students.
Videos, in particular, come in handy for learning this topic. They allow students to follow the process of bacterial identification step by step. This way, they can more easily master the concepts.
Interactive simulations are even better. They let students perform lab techniques in a safe, computer-generated environment. The experience is a lot like working in a real lab, but it’s much safer. If they make mistakes, there is no risk of harming themselves or getting sick. Once they master the technique in the virtual world, they will be more confident as they perform actual lab work. The image below is from Labster’s simulation entitled Identification of Unknown Bacteria: Help save baby Kuppelfangs from an epidemic.
Students must first have a good grasp of a few foundational concepts to better understand how to identify unknown bacteria. Here are some of those basics that students need for this topic.
Bacterial culturing is the practice of growing bacteria in the lab. The nutrients bacteria need are provided by the culture medium, which can either be liquid (broth) or solid (agar). Other conditions that are important for bacterial growth, such as the temperature and gas composition, are regulated by an incubator. Researchers can tweak the settings of the incubator to control temperature, gas composition, and agitation (stirring).
Aseptic technique is used to ensure a "clean" lab environment. It is essential to ensure the reliability of experimental results. These practices are especially important when working with microorganisms. A single spore or stray bacterium can contaminate an entire plate or culture vessel.
In microscopy and histology, staining is a technique to increase contrast in biological samples. Stains and dyes may interact with specific tissues, cell populations, organelles or proteins within the sample, which allows them to be more easily discerned.
Selective media contain agents that allow selected bacteria to grow, but inhibit the growth of others. The inhibitory agents could be antimicrobial drugs, dyes or alcohols.
Differential media distinguish different bacteria types based on the culture's appearance. Differential media contain one or more factors that cause bacteria with certain metabolic or culture characteristics to look different from other bacteria growing on the same agar plate. This type of medium is also sometimes known as an indicator medium. In response to components of the media, the bacterial colonies might change color or affect the appearance of the medium through the production of extracellular enzymes. Examples include blood agar and MacConkey agar.
Closely related organisms can be differentiated using a series of biochemical tests that identify various metabolic properties of different bacterial species. A single biochemical test is usually insufficient to identify an unknown bacteria, but different biochemical tests can be combined to identify a bacterial species successfully. Kits that are designed to identify common pathogens are commercially available. Biochemical tests may also be critically combined with other bacterial identification methods, including differential or selective media and staining. Examples of these tests include the catalase and oxidase tests.
Students who have no experience in microbiology may find this topic intimidating. For this reason, it’s important to use actual experience to build their confidence. It’s helpful to have students practice staining, biochemical testing, and preparation of differential media, among other things.
Once students get the hang of the basic techniques, they will be equipped to handle actual experiments in the lab. They will already be familiar with routine methods and be more confident in identifying unknown bacteria.
If actual lab work cannot be done, video demos and interactive simulations prove useful. Simulations like those found in Labster can help students have the necessary skills they need before embarking on actual lab work.
Virtual lab simulations are excellent tools for teaching the identification of unknown bacteria. Labster is determined to deliver fully interactive advanced laboratory simulations using gamification elements like storytelling and scoring systems while exposing students to an immersive, realistic, 3D environment.
Check out this simulation called Identification of Unknown Bacteria: Help save baby Kuppelfangs from an epidemic at Labster. This virtual lab allows students to perform decontamination and antibiotic selection in a safe, computer-generated environment. With this, students will gain the confidence to eventually perform the procedure on their own in an actual lab.
The image below is an example of what students can explore in the simulation.
Please take a moment to check out Labster’s Virtual Lab called Identification of Unknown Bacteria: Help save baby Kuppelfangs from an epidemic or get in touch to find out how you can start using virtual labs with your students.
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