I grew bacteria. Is it Staphylococcus Aureus?

I recently swabbed my mom's hand for a science project. I put the bacteria on a nutrient agar plate, and several days latter, there are large amounts white fuzz, black dots, frown dots, and some yellow dots. One yellow dot is a few mm in diameter and has a slight elevation. Tiny lines come out from the middle. The other yellow dots are small and scattered. A friend said that those bacteria could be staphylococcus aureus. He never saw it, but I told him about "small yellow circles". I read somewhere that many people carry this but are able to fight it with there immune system. Is this true? Should I be worried at all? Is there a way to be sure? Also, can nutrient agar grow this pathogenic bacteria? I read somewhere that it doesn't grow pathogenic bacteria selectively. What does that mean? Sorry for the large amount of questions, but I would really appreciate any help!

I grew bacteria. Is it Staphylococcus Aureus?
The short answer is you don't need to worry. A problematic staph infection would look like infected skin. It would be hot and hurt. It would probably be at a cut or injury. We would be surprised if you didn't grow anything froma person's hand.


You are very unlikely to grow pathogenic bacteria because your nutrient agar is a very different environment from the inside of your body. The fuzzy colony is almost certainly fungus. other than that it is hard to tell with any certainty the kind of bacteria based on just looking at the colony.
Reply:30% of people carry staph on their skin. We all carry heaps of other assorted bacteria on our bodies, different ones in different places.





Nutrient agar is safe to use in school science laboratories because it does not selectively grow pathogenic (disease causing) bacteria.





Hope that helps.





Cheers

ivy