Bacteria Science Fair Project

[deleted-739341]

Hello. I am a student in 8th grade, and I have recently started a science fair project for my school. My scientific question is as follows: "Does generic allergy medicine kill bacteria colonies found in everyday life?"

I know how to grow the bacteria in petri dishes, but that's just part one of the procedures. My problem is that then I would have to reopen the petri dish to apply a small amount of liquid or crushed allergy medicine, which could open a door to a whole lot of problems like affecting the bacteria in the petri dish with microorganisms in the air where I am testing and releasing potentially harmful bacteria onto myself and into the air around me.

Is there a better way of going about this experiment or at least a way to avoid the problems mentioned above? I would appreciate any knowledge given.

Best regards,
Carlo Polisena
([email protected])

[deleted-674917]

Hi Carlo,

I would love to help you but I have a few things to discuss first!

An allergy is caused by our body's own immune response to certain objects in our environment (e.g. pollen or peanuts) and is very rarely caused by bacteria (what bacteria cause are called infections). Our immune cells recognize an object (antigen) as foreign and harmful, and decide to start a response (basically like a fight that the body starts) to get rid of it. Some of the effects/symptoms of a bacterial infection can be similar (like redness and fever) and that is because the body will also use a similar immune response to fight bacteria (parts of bacterial cells are recognized by our bodies as antigens).

Now what an allergy medication does is to suppress this immune response but it does not have the ability to directly affect bacteria and kill them, which is where antibiotics come in. Therefore it is unlikely that generic allergy medicines will kill bacteria.
Here is some information about allergies:
https://www.mayoclinic.org/diseases-con ... c-20351497

I'm wondering if what you are really asking is, if the use of allergy medications can affect the normal growth of useful bacteria in our bodies? That is an important question because overuse of medications could alter our bodies in such a way that resident bacteria may grow faster (or slower) than usual. However this is hard to test on a petri dish as the medicines will not affect bacteria directly.

My second question to you is, what is the source of the bacteria that you are planning to grow? Are you thinking of just exposing a petri plate to air and letting colonies grow? Or do you want to isolate them from soil or coins or get a stock from your school laboratory? This is important to know in order to figure out the remaining steps and also answer your specific questions. Do let me know!

Hope what I have mentioned so far helps you to think about your project better and find out more on this topic. I will also be better able to help you with planning your experiments once you get back to me.

MS

[deleted-739341]

Hi!

Thank you so much for answering quickly and for giving so much detail!

This science fair idea was sparked by an article I found titled “Common Allergy Medication May Be Effective in Starving and Killing Bacteria.” (link below)
https://www.prnewswire.com/news-release ... 33483.html
What the article is stating is that allergy medicine itself doesn’t EXACTLY kill bacteria, but rather a certain component of it does in a few types of bacteria associated with Lyme disease. I am asking, can this general allergen medication starve and kill other types, which I could find no evidence of in my research.

But if you were to think of a better type of medication, like an antibiotic I could use, please tell me.

Regarding the source of the bacteria, I was hoping to find a harmless, concentrated source to use.

Again, thanks!

Sincerely,
Carlo Polisena.

[deleted-739341]

Hello, MS!

There’s just two things I forgot to mention in my last note.

The first has to do with the allergy medication. How the allergy medication (Claritin) is working against this type of bacteria is that it is preventing a resource the bacteria needs to keep its metabolic processes going from entering the cell envelope, thus starving and killing bacteria. This is why I picked allergy medicine.

Also, I think, along with my question in my first post about my procedure, I would like to discuss what bacteria to find. I am just stuck on this procedure part, and I do not want to advance any further into the project without making sure my question is testable.

Sincerely,
Carlo Polisena.

[deleted-674917]

Hi Carlo,

Thank you for bringing this article to my attention and explaining the rationale for your project. This is quite unique and should make an interesting and definitely testable project question.

You already know that this could be a very specific effect on the Lyme disease causing bacteria. I didn't find any similar reports in other bacteria with antihistamines like loratadine. The metal transporting systems of other bacteria could be slightly different and hence resistant to its effects. Keeping that in mind, I would try more than one kind of bacteria if possible. One will obviously be E. coli but please check with your school what other safe non-pathogenic bacteria you can get and use in your laboratory. And yes I would start with concentrated pure cultures of each kind.

Now let's say the effect is specific for Borrelia burgdorferi. In that case you will probably not see any change in growth in the plates with the allergy medication. In order to interpret this correctly, you need two controls - For each kind of bacteria that you are testing, you should check also their growth on i) no medications (your negative control) and ii) a medication that should definitely kill or inhibit at least, like an antibiotic (your positive control). Ampicillin/Carbenicillin is a good antibiotic to try.

Now coming back to your original questions: "My problem is that then I would have to reopen the petri dish to apply a small amount of liquid or crushed allergy medicine, which could open a door to a whole lot of problems like affecting the bacteria in the petri dish with microorganisms in the air where I am testing and releasing potentially harmful bacteria onto myself and into the air around me. "

First, you should plan to use known non-pathogenic bacteria that are safe to experiment with (rather than unknown species isolated from our surroundings) to avoid any risks to yourself. Second, in such experiments usually the antibiotic/medicine is not added to a plate where bacteria is already growing. You should start with two kinds of plates - your test plates that already have the allergy medicine spread evenly on the agar surface (in liquid form and allowed to dry) and your control plates. You then inoculate all plates with equal amount of bacteria and see if they grow slower in presence of your test substance and antibiotic control, than in the negative control (where growth should be really robust). Also if you work in a clean, dry, dust-free place and don't expose your open plates too long during addition of the medicines or during inoculation of your test bacteria, you should be fine!

I hope this answers your concerns for now. Please feel free to get in touch with me if you have more questions or if you want to discuss your findings when you start the experiment.
Good luck!
MS

[deleted-739341]

Hello, MS.

This was a great help. Thank you so much! I really appreciate it.

I am still in my research stage, and I will not be testing until mid-September. When I have my results, I will gladly send them to you along with a brief conclusion for your viewing.

Regards,
Carlo Polisena.

[deleted-674917]

Hi Carlo,

I'm very happy to hear that you found our discussion useful. I'll look forward to your results but feel free to reach out if you need to discuss again, when you start setting up your experiment! It's very natural to have more questions once you start getting into the thick of things

Best wishes,
MS

[deleted-739341]

Hi, MS!

I am starting to put together my actual experiment and gather my materials! Yay! This is the fun part. A while back, you had suggested I use a negative and a positive control. Do you think that, instead of purchasing disks of ampicillin, I should use iodine. The reason I am asking is because iodine comes in a set of petri dishes and agar I am using, so that would be another reason to purchase it. Or do you think I should stick with the antibiotic?

Sincerely,
Carlo Polisena.

[deleted-674917]

Hi Carlo,
Conducting the actual experiment is truly the most fun part in science! I'm really happy that you are enjoying it so far!
Yes, you can certainly use iodine as the positive control if that makes your experiment design easier. Iodine is a broad spectrum antimicrobial so it should be fine to use as a substance that should definitely kill your bacterial strain(s).
Hope this helps!
Good luck- and again don't hesitate to reach out!
MS

[deleted-739341]

Hi, MS.

A final question I had about my procedures portion of science fair is, do you think proper results would be gathered if I just count the bacteria colonies that have grown on the agar in the two controls and the experimental? The reason I am asking is because a viable plate count, which would be the other option, is very complicated, and I'm not confident I would do it right.

Sincerely,
Carlo.

[deleted-674917]

Hi Carlo,
Yes counting colonies should work. It's a good proxy for what's viable because a colony that you can see by the naked eye has reached that size by actively multiplying in numbers. So they are viable at least under those conditions.
Make sure you get no (or much fewer) colonies on your iodine/antibiotic control though!
Good luck!
MS

[deleted-748903]

Hi there,
Counting colonies would be a great idea.
Here's a tip about colony counting on plates:
Because you might have a highly populated plate that could make counting difficult, I recommend using a sharpie or other marker to draw a dot on the bottom of the dish after every colony you make a tally for, that way if you miss any, they will be clearly unmarked by the sharpie, so you know you haven't counted them yet.

Another idea is that you can draw a grid on a sheet of paper, then place your dish on top of the paper and count colonies in a methodical order from grid square to grid square so you don't accidentally miss any or count them twice.
There's more info on how to do that here:
https://sciencing.com/count-colonies-mi ... 17859.html

Let us know how it turns out; your project is super exciting!!

Best of luck,
lmp1341