When the bacteria that are sus... ... middle of paper ... ...inistration. 7-27-05: http://www.fda.gov/fdac/features/2002/402_bugs.html Davies, P. (1999, March). Multi-Drug Resistant Tuberculosis. Multi-Drug Resistant Tuberculosis. 7-27-05: http://www.priory.com/cmol/TBMultid.htm Kimball, J.
Test for Detection of Sugar in Milk Procedure: put 1ml sample in a test tube and then add 1ml of Sugar Reagent. place the test tube in a boiling water btah for 5min. presence red color indicates the presence of added sugar/sucrose in milk. Result : Red colour is seen so sugar is present B. Test for Detection of Salt by the use of Salt Reagent Add of salt in milk is mainly resorted to with the aim of increasing the corrected lactometer reading.
A feather out or cloudy appearance of the test tube identifies a positive mobility result. After conducting the gram stain test, we still needed to confirm that the bacterium was truly a gram negative or gram-positive bacterium. The MacConkey media was used to grow gram-negative bacteria and inhibit the growth of gram- positive. The bile salts and crystalviolet ingredients are selective against gram-positive bacteria; it can also be used to differentiate between gram-negative bacteria. The MacConkey media allowed Providencia stuartii to grow in the test plate.
RESULTS Unknown 3 was received in Trypticase Soy Broth. A Gram test was immediately performed to reveal that the bacterium was a Gram positive cocci. Once the morphology and Gram stain were determined and the presence of growth on a Trypticase Soy Agar slant was apparent, two tests were used to narrow down the list of possible organisms; those tests were the Methyl Red test and Urea hydrolysis. The Methyl Red test is used to distinguish an organism’s ability to ferment mixed acid, which is verified by the change in color of the Methyl Red broth after a reagent is added. There was no change in color of the broth which indicated a negative result.
In order to identify an unknown bacterium a variety of tests can be performed. The unknown bacterium that underwent a few of these tests was determined to be Escherichia coli. A Gram stain, citrate utilization test using Simmons citrate agar, and a urease detection test with phenol red were performed on the assigned bacterium. The unknown bacterium was determined to be E. coli because the tests concluded that the specimen was Gram-negative, bacilli, citrate utilization negative, and urease production negative. It is concluded that E. coli cannot utilize citrate as its sole carbon source and it cannot convert urea into ammonia and carbon dioxide.
Biochemical testing helps us identify the microorganism present with great accuracy. The tests used in this experiment are rudimentary but are fundamental starting points for tests used in medical labs and helps students attain a better understanding of how tests are conducted in a real lab setting. The first step in this process is to use gram-staining technique to narrow down the unknown bacteria into one of the two big domains; gram-negative and gram-positive. Once the gram type is identified, biochemical tests are conducted to narrow down the specific bacterial species. These biochemical tests are process of elimination that relies on the bacteria’s ability to breakdown certain kinds of food sources, their respiratory abilities and other biochemical conditions found in nature.
Based on the fermentation testes the microbe did ferment Glucose, Sucrose, lactose and Maltose. Si... ... middle of paper ... ...ll biochemical tests performed came out as expected except for the starch and urea digestion. On the first test starch shows a false + test and then on the second test it comes as a negative result. The same thing happened with the urea digestion it showed a false + test on the second test as a negative result, matching the result of a known bacterium, staphylococcus aureus.Therefore, it was concluded that unknown #79 was staphylococcus aureus. References Community college of Denver (2014).Introduction to microbiology laboratory manual.Boston,MA;person Learning solution Oxidative/fermentation glucose test.
I concluded that the unknown organism was Staphylococcus epidermis based on numerous tests performed in the laboratory which I will discuss in detail throughout this paper. One of the first tests performed was the Gram Stain. The Gram Stain differentiates bacterial organisms according to their cell wall structure. Gram-positive cells will stain blue to purple whereas Gram-negative cells will stain red to pink (Lab Handout; Gram Stain). Upon performing the Gram Stain on my unknown, I concluded that it was a Gram-positive cell due to the purple color when viewed under the microscope.
Med Microbiol Immunol 2013; 202(2): 95-104. 26. Jacobsen M, Repsilber D, Gutschmidt A et al. Candidate biomarkers for discrimination between infection and disease caused by Mycobacterium tuberculosis. J Mol Med (Berl) 2007; 85(6): 613-21.
Based off of the gram reaction, the tests I chose to do were the Oxidase, Sulfur reduction, Indole Production, Motility(SIM), Citrate Utilization, Urease and Methyl Red and Voges-Proskauer (MRVP) Test. Microscopic Examination: The cell morphology is an important characteristic that helps identify bacteria. The three main shapes of bacterial cells are coccus, bacillus, and spirillum (3). Stains were used in order to facilitate the viewing of bacterial cells under the microscope. A gram stain is a differential type of stain that determines whether a cell is gram-positive or gram-negative.