Interesting...

So we have more results and possibly a contradictory one. Lets start with our Thioglycollate test which shows us the type of environment our bacteria can grow in. In our test tube, the bacteria grew all throughout the tube! This told us that our bacteria H has facilitated growth meaning it can grow with or without oxygen in the environment.

So it's hard to see, but there is bacteria all throughout the tube

The school photographer also came to our class in order to take some picture. It was a little awkward at times to say the least.

Anyway, moving on to other things.

Next we looked at our last enzyme test which was on DNA agar. We had to add hydrochloric acid to the plate in order to see the result.

Our bacteria was as you can guess.........negative. For each of these tests we split the plates in half so our bacteria is the yellow one and it should be growing in the shape of J and M. With this test being negative, it tells us that our bacteria does not have the enzyme used to break down DNA.

Now we will look at our last five tests. These were all on selective or differential media. They will tell us where our bacteria can grow.



First is blood agar. Our bacteria grew, but did not have the ability to lyse red blood cells (in other word break them down).

The next one was EMB (eosin methylene blue). This one was negative as it was lacking any growth what so ever. Some of these tests we don't know yet what the results mean, but Dr. P. assured us that we will be learning about it in lecture soon.

The Mannitol Salt agar was then under scrutiny.  Since this agar is a salt most bacteria won't grow here because of the hypertonic state. The salt will draw all the water out of the bacteria and it will die. This is why pickled foods last so long because lots os bacteria cannot grow in the salty environment. Our bacteria is the one above the line and it did not survive.

Our fourth one is the MacConkey agar. This one is suppose to inhibit gram-positive bacteria. Other then that all we know it that we had no growth. What this result means, again we do not know yet.

The fifth and final test to look at was the PEA test (Phenylethyl Alcohol Agar). This one was interesting because this agar inhibits or slows gram-negative growth. We beleaved that from our gram stain that our bacteria was gram-negative. The problem though is that we has growth on this plate!!

The amount is very small so it could be that our mystery H bacteria was still able in some way to grow just a tiny bit, but it still makes us question if our original thoughts was wrong. Next week we may repeat the gram stain and see if we still come up with the same results. Until then, have a safe weekend!!

More samples and Strep throat swabbing practice

We are now half way through our tests for our mystery bacteria H. Today we looked at the streak plate we did last week. The bacteria grew on the surface so it must be aerobic. To see if bacteria H has any peroxisomes we poured hydrogen peroxide on the surface of the plate. Our's was slow to bubble, but after a few seconds it started to react. This told us that our bacteria is definitely aerobic because the catalyst needs to be present in order for there to be oxygen for the bacteria to grow.

We shared our plate with another group so our bacteria is the yellow one.

 We also inoculated seven more tests. Five of them are called differential media tests, one was to test for the hydrolytic enzymes for DNA, and one was to test the anaerobic or aerobic type of bacteria.

Anaerobic or Aerobic?
After inoculating 

Anaerobic or Aerobic?
Before inoculating 

The five test we started on different media were:
EMB, Blood, PE, Mannitol Salt Agar, and MacConkey Agar

We got to be all official and use the disposable tips to inoculate!!
So the last thing we did was practice swabbing each other's throats for strep. We didn't test them all, but we got to practice the technique. It was super fun. hardly anyone gagged so I hope we did it right! Anyway, on Thursday we will see if our bacteria has decided to be interesting or not. We shall see.

Urea! Things are looking up.

Thursday, October 17th

WE FINALLY HAVE A POSITIVE TEST!!!!

Our test for Urea came back positive. Because of this we can conclude that our bacteria can hydrolyze urea. 

Not surprising however, the rest of our tests came back negative. Here's a couple of examples of our negative tests:

                   Nitrate:                                                                                                 Indole:

After we checked our test results we completed an oxidase test. 

Our results came back negative:

Classic Bacteria

Tuesday, October 15th

We got our results back today from the sucrose, lactose, glucose, and TSI tests and the verdict is........

....*drumroll please*....

ALL NEGATIVE. 

This is a classic occurrence for our unknown bacteria. It's a stubborn one!


Here's some pictures from our negative results:

Sucrose:

                         

Glucose:

TSI:

We also inoculated our bacteria for some other tests. Here are the ones we prepared:
Indole
Urea
Nitrate
MR
Citrate
TSA

Indole:

        

Urea:

Nitrate:

Methyl Red (MR):

Citrate:

More results to come on Thursday! Maybe next time we will finally get a positive test. We'll have to wait and see! 

Test Results!!!

So, at the end of last week we prepared five different tests to see if our unknown bacteria H had any hydrolytic enzymes (digestive enzymes). The results though were less then impressive though. Here they are:
Starch test: Negative
Casein Test: Negative
Lipid Test: Negative
Gelatin Test: Negative
Litmus Milk: Negative

Here are the pictures

Lipid Test

Casein Test

               

Litmus Milk Test

Starch Test 

Gelatin Test

So we basically decided that our bacteria is boring. Anyway, not much came from those tests. This bacteria is really resisting our detective efforts. Well, we won't be discouraged! The last thing we did was prepare one more series of tests. These were to see if our bacteria breaks down any sugars. We tested Glucose, Fructose, Lactose, and triple sugar iron. 

Hopefully we get some results!

A Whole Buch of Tests!

Thursday October 3, 2013

First discovery of the day was that our bacteria was not motile. Unfortunately, it looked about the same as it did on Tuesday. We were pretty bummed, we wanted to see it move under the microscope! 

Next we completed several inoculations to test for starch hydrolysis, casein hydrolysis, fat hydrolysis, litmus milk, and gelatin hydrolysis. 

Starch hydrolysis:

Casein Hydrolysis:

Fat Hydrolysis:

 Litmus Milk test: 

Gelatin Hydrolysis: 

After we completed the inoculations, we stored the bacteria at 25 degrees Celsius. 

We then looked at the broth inoculation we had done on tuesday, and at first didn't see any bacteria growing. We reinoculated our bacteria in the broth. 

After that, Dr. P came over and told us that we actually did have bacteria growing! Pretty awesome. We then practiced the droplet slide technique under the microscope. Adios! 

Motility Testing

Tuesday September 1, 2013

Today we began lab by preparing a new sample of our unknown bacteria. We're preparing our bacteria and inoculating it to determine if it is motile or nonmotile bacteria.  We'll have to wait until Thursday to know for sure, but this is what the bacteria should look like:        

The anticipation is too much! 

To test the bacteria's motility, we used the stab technique process. We used an semi-solid agar solution to inoculate our bacteria. 

After we used the stab technique, we could see a line of bacteria in our test semi-solid agar solution. So cool!

Next we repeated the stab technique but this time inoculated our bacteria in a broth.

After we finished the inoculation, we put our bacteria in the incubator at 25 degrees Celsius. Now we wait!