Science Buddies: "Ask an Expert"

Hello!

I am conducting a summer research project and to do so, I need a sample of p. acnes. I'm not sure how to obtain it, though. I've tried looking for a way to purchase it online, but I haven't been able to find a retailer/supplier.

Does anyone have any tips on where I can get a sample?

I want to do a project where I test how different types of pillowcase fabrics affect the rate of growth of acne-causing bacteria, p. acnes. Unfortunately, I do not have access to a lab at this time and I will be performing this research at home. This means I won't have access to an incubator or special types of agar which p. acnes needs in order to grow effectively. I have also not been able to secure a sample of p. acnes, as they are all too expensive or because I do not have the required permits.

This brings me to my question. I stumbled upon a science buddies experiment and kit where students can test which acne medications are most effective. The kit provides students with a sample of E. coli. Is E. coli a comparable bacteria to p. acnes? Will the sample provided in the science buddies kit react similarly to how p. acnes would react when I test it on the pillowcase fabrics?

Thank you all for taking the time to read this and for trying to help me!


Moderator note: It looks like both of your posts relate to the same project so I've combined them into 1 post. This will help the experts to see both of your questions and ensure that your message appears in the "unanswered" queue! Thanks!

Hello,

Sounds like you've got a solid project started with a very intriguing idea! Yes, something like C. acnes would probably be difficult to acquire. E. coli, if that is what you can get your hands on, is a workable substitute. Often in research, we have to use a model that is safer, easier to work with, and/or more ethical in order to study a comparable specimen. Just make sure that, in your notes and discussion, you make sure to remark on any differences there could be between the experimental model and the actual bacteria you meant to represent with it.

There will surely be differences, and you may need to do more in-depth research for that. For instance, the two bacteria have different growth rates; a cursory search indicates that E. coli has a significantly faster doubling rate than C. acnes. Their metabolic systems are also probably different (e.g. anaerobic vs aerobic; how would this impact growth?). Another thought I had was Gram-negativity; E. coli is Gram-negative, while C. acnes is Gram-positive. This has implications for drug response, which may or may not be pertinent.

Whatever you find, make a note of it and mention it as a limitation of your design. You're not at fault for not being allowed to handle C. acnes, but recognizing the implications of your research design is part of good scientific practice.

Hope that helps!

Thank you so much for your helpful response!

I'm going to go ahead and use the E. coli sample for my experiment. I will definitely be sure to do some more research about the differences between the two bacteria and make note of the differences in my paper.

Also, I hadn't realized that even in professional research settings, scientists use substitutes that are safer and more ethical for conducting research. Thank you for telling me!

Again, thank you so much for your response! It was really helpful and reassuring!

Sorry I didn't see this earlier. Glad I could help! Yes, in research we make those "compromises" a lot; I mean, there's a reason why mice and rats are so common in biological research - they're used as models for a lot of studies that eventually hope to reach human testing, whether for ethical or logistical concerns. I encountered similar issues myself in my high school project on fungal infections. One judge did briefly grill me on the differences between my model (bread mold) and the types of fungus that cause more serious infections, but I defended myself with what I knew and it seemed to work out fine.

Good luck with your project!