Back at it this week with discussing whether or not our soil microbe is resistant or sensitive to certain antibiotics. First, the antibiotics that we tested were; 1-erythronycin, 2- cabernicillin, 3- ampicillin, and 4- tetracyclin. The numbers are associated to where each antibiotic was placed in the pictures below.
The first picture is of S.Aureus, which as seen in the photo is sensitive to antibiotic 1 and 4, which are erythronycin and tetracyclin . S. Aureus is resistant to drugs 2 and 3, which are cabernicillin and ampicillin. This is shown by how there is no growth around numbers 1 and 4, showing that the drug inhibited the growth of this bacteria.
This next picture is of S.epiderdimas, and is a clear example of how all four of the antibiotics inhibited the growth of this bacteria, showing that the organism is very sensitive to the drugs used. Once again, there is no growth around the disks (drugs) which clarifies that it is sensitive.
This next picture is of E.coli, and is another clear example of how this organism is sensitive to the drugs used. Once again, there is no growth around the disks (drugs) which clarifies that it is sensitive. The results from E. coli look almost identical to S. Epiderdimas.
Lastly, this picture is of our unknown soil microbe which shows that our microbe is resistant to all four of this antibiotics. Now, it makes me a little cautious to definitely come to this conclusion due to the fact that our soil microbe is a very slow growing bacteria. Our protocol stated to check our results 24-48 hours after we inoculated it, and this is the picture from after 48 hours. Although I followed the protocol designed, I think with 3-4 days could have given us a better indicator of whether our microbe was resistant or sensitive. But, the results shows our microbe is resistant to all four antibiotics, and even with 48 hrs. to grow, I think we would have seen, at least, a little inhibition if it was sensitive.
Our unknown microbe was resistant to all four of the drugs, S. Aureus was resistant to two and sensitive to two, while both S. epiderdimas and E. coli was sensitive to all of the drugs. Since the other organisms tended to be sensitive to all four of the drugs, that is one reason why I am a little skeptical about our microbe being resistant to all four of the drugs. Once again, it could be due to the fact that our microbe was very slow growing.
So, last week we threw Streptococcus back into the equation with determining what our soil microbe could be due to the blood agar test. We are still not 100% sure which bacteria our unknown is, but according to ours results, I would narrow it down to Lactobacillus, Corynebacterium, or Streptococcus. I think the next test done should be determining whether or not each bacteria is anaerobic, because this would eliminate either Lactobacillus or Corynebacterium from the decision with that data. Then, we could narrow the options down to two and run another test which would determine which soil microbe is ours.
Last time blogging :((((((
M&M Microbiology
