The Last Day!

Today was our last day in class and lab for Medical Microbiology. The groups finished up their presentations (we were the last ones to go) and people finished up their individual projects. We got to see the results of our animal and human mouth swabs. The human mouth turned out to have the highest number of bacterial colonies but the cat had more different types of bacteria then the rest.

Top: Cat; Goat

Bottom: Rabbit; Human; Dog

Top: Human; Goat; Dog

Bottom: Cat; Rabbit

More work on our project

Today in lab we listened/watched one group's presentation then started working on our projects. We used our samples that we swabbed on Tuesday to make spread plates. We used a pipet with tips to get 100 microliters of each sample to spread on the plates. Then we used a glass rod that was sterilized with rubbing alcohol that was burned off with the Bunsen burner. Then we put them in the incubator that is set at 37 degrees Celsius. We'll check the results on Tuesday which is our last day of lab for this class.

Uhm can we leave and go swab some animals?

Today in lab we just looked at the results from last week. It showed how the albumin reacted with the antigens.

Then the rest of lab was used to go gather swabs of the animal mouths for our project. We used Teresa as our human test, Hannah's cat, dog, goat and rabbit. The only test that didn't mind the swab was the rabbit.

"We're fresh out of AIDS over here"

Yesterday in lab we did too small experiments before we were done for Thanksgiving break. The first was Immunodetection. There were 3 parts to this experiment that were all done on the same petri dish. Before we started the exercises, we used a pipet to create small holes in the agar. For the first exercise, we put green dye in one hole, red dye in the second, Barium Chloride in the third and Potassium Sulfate in the fourth. For the second exercise, we added Bovine Albumin to the first hole, Goat Anti-horse Albumin to the second, Goat Anti-bovine albumin to the third and Goat Anti-swine Albumin to the fourth. The third exercise was similar to the second in that it used Goat Anti-horse Albumin, Goat Anti-bovine Albumin and Goat Anti-swine Albumin in the same holes but it used Hamburger Extract in the first hole.

The second experiment was an ELISA or enzyme-linked immunosorbent assay test that detects antibodies in someone's blood. We labeled a 12-well strip with 3 +'s, 3 -'s, 3 number 1's and 3 number 8's. Then we used a pipet to transfer 50 microliters of the purified antigen to all 12 wells, waited 5 minutes then washed the wells with buffer. Then we used another pipet to transfer 50 microliters of the positive control to the +'s, then 50 microliters of the negative control to the -'s, then 50 microliters of number 1 to the 1's and number 8 to the 8's. We waited 5 minutes then washed the wells with buffer. Then we used a pipet to transfer 50 microliters of secondary antibody to all the wells, waited 5 minutes then washed with buffer. Then we transferred 50 microliters of enzyme substrate to all the wells. We waited 5 minutes and then noted that the +'s turned blue along with the 8's meaning they were positive for the antibodies for HIV.

"Everybody grab a spoon!" "Umm, I'm not eating that!"

On Thursday we checked the experiments that we did on Tuesday.
First, we checked the plate that we treated with UV light. We only treated it for 30 seconds which turned out to not be enough time. Dr. Pathakamuri told us that bacilli bacteria generally need a longer treatment to be killed.

Then we checked how the Steripen affected the cocktail of all the class's unknowns. It actually killed a large amount of bacteria, only leaving a few colonies.

Then it was time to test the homemade yogurt. This made a lot of people nervous. Hannah and I didn't personally try it but other people said it wasn't too bad but one sample was a little sour.

The top was made from the Kefir milk and the bottom was from the already made yogurt.

For the rest of lab, we watched a few videos on ideas we talked about in class and finalized what each group was doing for their lab experiment. Hannah and I are comparing swabs from human, dog, cat, cow, chicken, rabbit and whatever other types of mouths we can find to see who has the cleaner mouths.

It's like a scientific approach to the mirror picture

Today in lab we used UV light to see if it will inhibit bacterial growth. Some hospitals use UV lights in the patient rooms as an antimicrobial approach. Dr. Pathakamuri showed us a container where they used UV light in this way.
Lisa made the comment of scientific mirror picture -->

Then it was our turn. We divided a plate in half and shared it with Teresa and Lisa. Each group streaked their unknown on their side. Then we divided the plate in half the other way and placed a notecard over half of each of our unknown. Then the plate was incubated for Thursday.

Then we got to see the Steripen. This uses UV light to sterilize water and make it safe to drink. Dr. Pathakamuri mixed all of our unknowns into water then made a control plate and then he used the Steripen in the water and created an UV light treated plate. Then the plates were incubated for Thursday.

The last experiment we did was making yogurt. First we boiled milk then cooled it down to 37 degrees Celsius. This was sped up by pouring it from cup to cup. Then we added Kefir to one cup and already made yogurt to another. Then it was incubated and Dr. Pathakamuri will check them tomorrow.

What is he doing with that glove??

Today in lab we finished the experiments we started on Tuesday.
Indole - After we added Kovak's reagent the top layer turned yellow which means tryptophan was not hydrolyzed.

Citrate - When we looked at the test tube the top of the agar had turned blue which means it is positive for using citrate.

Urea - The color slightly changed but we left it in the incubator to see if it is actually a positive result.

Nitrate - We added 5 drops of reagent A and 5 drops of Reagent B and mixed the broth. Ours made red bubbles and when we mixed it more it turned to a pink color. This is a positive reaction meaning nitrite ions were present.

Oxidase - We swabbed our unknown then dripped oxidase onto the swab. It did not change color so it was a negative result.

 

Antibiotics - Our plate showed that Tetracycline slightly worked, clearing 1.3cm which means it is not sensitive, Vancomycin cleared 1.8cm which means it is not sensitive, Chloramphenol cleared 2.0cm which means it is sensitive and Neomycin cleared 1.8cm which means it is also sensitive.

While we were doing our experiments, Dr. Pathakamuri was playing with a glove and made MRSA.

Movie Time

Last Thursday, the 3rd, we started to watch the movie Outbreak. It shows how a bacteria can quickly spread throughout many different areas of the world. Today we inoculated a nitrate broth tube to see if our unknown is able to reduce nitrate to either nitrite or nitrogen gas. We then did the indole test to see if our bacteria can split tryptophan into indole and pyruvic acid. Then we did the citrate test to see if it uses citrate as a source of carbon and energy. The urea hydrolysis test was next. This was used to see if our unknown can hydrolyze urea. Then we streaked a plate with our unknown and placed penicillin, vancomycin, novabiocin, tetracycline, erythromycin, chloramphenol, and neomycin patches in a pattern to see which antibiotic our unknown is sensitive to. Then we finished the movie. :)

Its a pretty pink color :)

Today in lab we needed to check our plates we streaked before the field trip. The Mannitol Salt agar plate showed colonies that were yellow in color. This means that our bacteria creates acid as an end product. The fact that our bacteria grew means that is uses salt or is a halophile.

Then we checked our MacConkey plate. This plate only allows gram negative bacteria to grow. If the bacteria would have been red then it would be a coliform bacteria. Ours was not colored so it is a non-coliform.

The last plate we checked was the EMB or Eosin Metylene Blue agar plate. This plate allows only gram negative bacteria to grow. And if the bacteria was a pink colored that means it is lactose-fermented. This means it could be Enterobacter aerogenes.

We didn't do any other experiments because we have our Fall Break coming up this weekend and we won't be in lab to check results.