Science Buddies: "Ask an Expert"

Hi!
I desperately need help elaborating on my topic. Im doing The Effect of Natural Antibiotics on Bacterial Resistance. I was thinking of how some bacteria become unaffected by antibiotics in the form of medication when it is taken constantly and wondered if natural antibiotics like garlic, honey, and turmeric if applied repetitively, could make bacteria not be resistant? If do this project, I'd need bacteria. Could I get non-expensive bacteria from maybe raw meat? I'm not sure how to carry out the procedure, what iId need, how to detect differences in bacteria before and after the experiment because I've never really worked with this type of topic in school. Please help me step by step!!!!!!!

I really would appreaciate any help. Thanks.

Hi,

First, if you're interested in a microbiology project, you need to read Science Buddies' guide to working with microorganisms, which can be found on the bottom right of this page: https://www.sciencebuddies.org/science- ... ndex.shtml . Also read the safety information on the top right!

You might also want to take a look at these Science Buddies projects, which have to do with antibiotic resistance: https://www.sciencebuddies.org/science- ... y&from=TSW, https://www.sciencebuddies.org/science- ... y&from=TSW, and https://www.sciencebuddies.org/science- ... y&from=TSW

That said, I am not sure if I understand what you are trying to do. Are you thinking we should substitute 'natural' antibiotics for 'medicinal' antibiotics (note: most 'medicinal' antibiotics came from natural sources!)? Or are you thinking of applying natural antibiotics to antibiotic resistant bacteria?

Hi,

I have decided to compare how well different natural antibiotics work against killing bacteria and not having the bacteria become resistant to each. I am testing garlic, turmeric, and honey. Are there any other natural antibiotics I could use? I predict turmeric will work best. I plan on streaking the bacteria in nutrient agar from raw beef first, then adding the antibiotic extract. It would culture for three days. I'd make the extract myself by pulverizing it and dipping a paper disc in it. The discs would be placed in the agar plate. I'd observe how the bacteria doesn't grow around the disc---zone of inhibition. Whichever zone of each is greatest and fastest formed works best, right?

To prove that an antibiotic also makes bacteria least resistant, I'd apply more of the same extract to the same plate used for it the first trial right? If the zone forms at the same rate, the antibiotic doesn't make the bacteria resistant. If the zone forms at a slower rate, or doesn't form at all, it makes the bacteria resistant.

Maybe as a side fact, I' d compare previous test results for pharmaceutical antibiotics with mine, because i want to persuade people that to fight against bacterial strains, natural antibiotics should be used.

If there are any flaws in this experiment, which I'm sure there are, please tell me what to do and address my questions.
Thank you.

Hi,

You have a very good idea for a science project. Melissa has given you good information on the basic techniques and safety involved in doing an antimicrobial project, however you need to do more background reading to develop this into a carefully controlled experiment. I’ll try to help you get started on this process.

Here’s an example of a project that included a study of antimicrobial activity of turmeric:

http://www.jyi.org/research/re.php?id=899

Please notice that the student used a minimal inhibitory concentration method to determine resistance, and that is an alternative to the agar plate method with discs. Please also notice that the student describes in great detail the exact details of the experiment, and you will want to do that also so anyone reading your project would be able to reproduce your results. One other detail that might be important is that the experiment included an extraction of the turmeric to purify the pure curcumin for the experiment.

If you use bacteria obtained from the surface of meat, you will likely have a mixed culture of different microorganisms, and this would not allow you to have a reproducible experiment. Generally antimicrobial resistance is measured using a pure culture of a single organism. If you isolate an organism from meat, you would need to do additional work to try and identify it, so it might be better to use a pure culture of a known organism for your project.

One parameter that is important in antimicrobial testing is the age of the culture and the number of organisms you perform the test with. Typically, a culture that has been incubated overnight is used to spread on the agar plate and the same number of organisms is inoculated onto the plate. So you will need to use identical conditions for each experiment so you can compare results.

Next, for this project, you will need to become an expert in the chemistry of turmeric, garlic, and honey. Here are two references using garlic:

http://www.ncbi.nlm.nih.gov/pubmed/10737231

Notice that the authors found the age of the garlic was important and they used just one microorganism in their study. The authors did additional work to fractionate the garlic extract by chromatography to characterize the antimicrobial activity.

http://www.ncbi.nlm.nih.gov/pubmed/12553397

This is an interesting study done with oral microorganisms (a mixed culture), but the authors still managed to have a controlled experiment.

Here’s a reference describing the mechanism of antimicrobial activity of honey:

http://jac.oxfordjournals.org/cgi/content/full/56/1/228

Please note the authors used various sources of honey and several isolates of the same microorganism in their study. They found that one particular honey (manuka honey) contained an unidentified phytochemical that was responsible for antimicrobial activity against Staphylococcus species compared to other honeys (this might be an idea for a unique project).

If you can’t open up any of the links I’ve included, let me know and I’ll print them out and upload them. I encourage you to do more background reading until you can identify a specific experiment that will add to the data that already exists on your topic. We want you to have a really great project!

Good luck.


Donna Hardy