How to Teach About Bacterial Isolation

Teaching students about the incredible bacterial diversity of the microbiological world can pose a challenge to professors and educators due to the:

• microscopic nature of the bacteria
• lack of significant morphological differences between strains and species
• limited availability of resources in undergraduate-level laboratories to teach microbiology
• difficulty in demonstrating vital microbiology lab techniques 

That’s why we’ve compiled these 6 helpful tips and resources for microbiology educators: 

1. Make Microbiology relevant to students’ lives

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Students may think of Microbiology as merely a class or lab, but it is intricately knitted into our daily lives and global policymaking. Having witnessed the Covid-19 pandemic, we should understand how the microbiological world can be extremely influential in our lives, travel, economics and policies. This makes teaching microbiology even more complex. 

As per a recent study by Salazar, C. B. et al., the cause of future pandemics is predicted to be bacterial species. (3) With the rise in antibiotic resistance, multi-drug resistance, lack of national health security policies in most developing countries, equipment of bio-terrorism in the 21^st century, etc, the danger of man-made bacterial attacks hovers over our heads. 

That’s one of the underlying reasons why it’s so important to shape our students into excellent microbiologists and bacteriologists who have sound thinking and an appreciation for their field. Being able to isolate bacteria can be a stepping stone for microbiology students and a boost to make them want to learn more.  

2. Strike a balance between prior knowledge and new concepts

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Students enter a course with vastly different backgrounds, leaving instructors with a dilemma as to where they should begin teaching a topic. It’s crucial that they get a general idea of how much their students already know about the subject. 

For example, they may need to know whether students are aware of beneficial versus disease-causing species of bacteria, the nature of bacteria as compared to eukaryotes and archaea (phylogenetic relationships), characteristic features of a cell to be described as bacteria, the various genetics, molecular biology aspects, etc can come handy before beginning bacterial isolation per se.  

As Cheryl J. Power at the University of Melbourne Department of Microbiology and Immunology pointed out in her editorial, taking this step can help students in the effective integration of new microbiological concepts while minimizing any misconceptions. (2) 

‍Bonus tip: Interactive polling tools like Top Hat, Poll Everywhere, and Google Forms are useful for determining the current knowledge base of your students so you can design your teaching plan accordingly.  

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3. Emphasize the importance of the bacterial isolation technique

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A report by Patrick D. Schloss and Jo Handelsman finds that the minimum bacterial species diversity on the planet is estimated to be 35,498. (1) 

Educators can introduce this fact as a way to help students get curious about how they could obtain a pure bacterial culture to study each of these individual species. After all, a pure bacterial culture can only be obtained after the isolation of the species of interest! Once their interest is piqued, you can direct their energy toward exploring and practicing the bacterial isolation technique to prepare them for their experience in the real lab. 

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4. Demonstrate bacterial isolation using interactive simulations as pre-lab learning tools

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Labster provides a detailed Bacterial isolation simulation that covers all the vital aspects like patterns of bacterial growth, aseptic conditions, plate streaking methods, selective media and more. The use of interactive simulations and animations as part of teaching can serve as a catalyst for learning at a deeper level. 

In a recent study, the use of simulations and interactive experience has been noticed to heighten the learner’s comprehension and understanding of the subject. (4)

Since bacterial isolation involves a number of novel aspects of science, it can be quite overwhelming for students and increase time and costs for educators. Labster interactive simulations and other learning tools can be a relatively quick and cost-effective way to introduce both demonstration and hands-on practice of microbiology techniques like bacterial isolation. 

Through an immersive environment and narrative story, students learn concepts like: maintenance of aseptic conditions, use of laminar flows, bio-safety cabinets, sterilization techniques and incubators, the concept of serial dilutions, and the preparation of media. They also learn vocabulary like stock and working solutions, etc. 

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5. Scaffold Microbiology knowledge with additional context 

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Equipping our students with the proper set of knowledge/tools prior to beginning lab handling can build confidence and help inform the depth of class discussions. 

For example, understanding bacterial isolation is impossible without knowing the bacterial culture conditions, i.e. temperature, oxygen and nutritional requirements. The image below showcases different types of bacteria based on their sensitivity to temperature.

Some helpful microbiology teaching resources from Labster include virtual labs on bacterial shape and movement, bacterial structures, working in aseptic conditions and bacterial growth. 

6. Expand interest with professional resources

Government and industrial R&Ds have developed webinars and compiled facts that can prove beneficial for learning the intricacies of the bacterial isolation procedure. These include:

• Cytena, a U.S.-based biotech firm conducts webinars where they educate learners about simple workflows for bacterial isolation from complex gut samples and the establishment of pure cultures. 
• Thermo Fisher Scientific compiled some Q&A resources related to bacterial isolation as presented in their microbiome research webinar. 

Additional resources to take students further

Preparing students for a bacterial isolation lab means activating their curiosity, piquing their interest, demonstrating how to perform the technique of bacterial isolation, and equipping them with pre-lab experiences that enable them to visualize and practice the proper method. 

Labster simulations support microbiology educators in conveying important learning objectives with engaging interactives that are easy to access. In addition to mastering bacterial isolation techniques, microbiology educators can offer their students deeper and broader content topics from Labster’s Microbiology Simulation Course Package.

Questions for reflection:

Which approaches to teaching about bacterial isolation have already worked well in your microbiology courses? 

Which new techniques are you planning to try for introducing how to do bacterial isolation to your students?

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References: 

1. Schloss, P. D., & Handelsman, J. (2004). Status of the microbial census. Microbiology and molecular biology reviews, 68(4), 686-691.
2. Burke, C., & Power, C. (2010). The challenges of teaching microbiology. Microbiology Australia, 31(1), 3-4.
3. Salazar, C. B., Spencer, P., Mohamad, K., Jabeen, A., Abdulmonem, W. A., & Fernández, N. (2022). Future pandemics might be caused by bacteria and not viruses: Recent advances in medical preventive practice. International Journal of Health Sciences, 16(3), 1-3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9092534/
4. Palancia Esposito, C., & Sullivan, K. (2020). Maintaining clinical continuity through virtual simulation during the COVID-19 pandemic. Journal of Nursing Education, 59(9), 522-525.

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