Bios242 Lab2

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iLab #2

Carbohydrate Tests

INTRODUCTION -

For this experiment we will be testing four different bacteria with four different tests, using glucose, lactose, and sucrose. Hopefully we will use the information from those test to be able to identify the organisms in each of the samples from the case studies. We will use the results from the four different tests along with the information of how different bacteria react to match up to the case scenario and identify the bacteria, then check to see if our guess was correct. The findings are that we were able to identify, by process of elimination, the four different test bacteria.

PROCEDURE -

These procedures were followed for all four media test samples. Label test sample.
Record Case study and Gram Stain results.
For glucose testing:
Select red glucose broth with durem tube.
Inoculate red glucose media.
Incubate for 24 hours.
Record results.
For lactose testing:
Select red lactose broth.
Inoculate red lactose media.
Incubate for 24 hours.
Record results.
For sucrose testing:
Select red sucrose broth.
Inoculate red sucrose media.
Incubate for 24 hours.
Record results.
For Identifying the four organisms:
View identification matrix and elimination hierarchy.
Make an educated guess with information from case study.
Identify organism.
Verify and record the correct bacterium.

OBSERVATIONS & RESULTS -

|Acid from glucose |Gas from glucose |Lactose ferm. |Sucrose ferm. | |Test bacterium 1 |+ |+ |+ |+ | |Test bacterium 2 |+ |+ |+ |+ | |Test bacterium 3 |+ |- |- |- | |Test bacterium 4 |+ |+ |- |+ | |

Test bacterium 1 - Escherichia coli

case study: A 4-year old girl was brought to the emergency room suffering from severe, watery diarrhea, lethargy, and nosebleeds. Emergency room personnel reported a fever of 101o F, blood pressure of 110/70, and heart rate of 72. Blood and stool samples were taken. Urine samples contained blood. The blood work revealed an acidic pH and abnormally low levels of platelets and erythrocytes. High levels of creatinine and urea were observed. This organism was cultured from various body fluids.

Gram stain results: gram negative rods.

Acid from glucose: positive.
Gas from glucose: positive.
Lactose fermentation: positive.
Sucrose fermentation: positive.

Test bacterium 2 – Enterobacter aerogenes

case study: Butch was given the assignment by his microbiology instructor to sample soils from a variety of habitats for microbes. This organism was isolated from soil he obtained at a local farm.

Gram stain results: gram negative rods.

Acid from glucose: positive.
Gas from glucose: positive.
Lactose fermentation: positive.
Sucrose fermentation: positive.

Test bacterium 3- Salmonella typhi

case study: A 31-year old graduate student from Peru visited the emergency room complaining of fever, headache, body aches, painful urination, and sore throat. Questioning by the emergency room personnel revealed he had returned less than two weeks ago from visiting home for the holidays and had been suffering from developing symptoms for at least six days. Their examination also revealed fever of 103o C, slow heartbeat, and a tender abdomen. He was admitted to the hospital for further tests. The next morning the fever and symptoms remained and clusters of small pink spots appeared on the chest and abdomen. The patient complained of severe exhaustion. Over the course of time, the fever dropped gradually and the symptoms subsided. This organism was cultured from blood, stool, sputum, and urine specimens.

Gram stain results: gram negative rods.

Acid from glucose: positive.
Gas from glucose: negative.
Lactose fermentation: negative.
Sucrose fermentation: negative.

Test bacterium 4 – Proteus vulgaris

case study: David washed his hands along with the others in his microbiology lab. Their...
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