Negative Unknown Lab Report

Gram Negative Unknown Lab Report

Abstract The Unknown Gram Negative bacterium inoculated in a Tryptic Soy broth medium was randomly selected from a group of other unknowns. In order to identify this unknown the seven different types of biochemical tests will be conducted on this unknown bacterium to identify it out of 6 possible bacteria; Escherichia coli(E. coli), Enterobacter aerogenes (E.aerogenes), Klebsiella pneumoniae (K.pneumoniae), Proteus mirabilis(P.miranilis), Pseudomonas aeruginosa(P.aeruginosa), and Salmonella typhimurium (S.typhimurium). The biochemical tests utilized were; Triple Sugar Iron Agar (TSIA) test, Sulfur Indole Motility (SIM) test, Methyl red test and Voges-Proskauer (MR-VP) test, Citrate test, Urea test,
Using a flamed inoculating loop, the pure culture of unknown number 25 was added to the MR and VP tubes. Afterwards the proper reagents were added to each tube. Three drops of methyl red reagent were added to the methyl red tube where the results were observed immediately and properly recorded. Fifteen drops of VP reagent A were added to the VP tube and mixed properly. Then five drops of VP reagent B were added and mixed properly. The VP tube was observed 10 minutes, and results were recorded. The citrate test was performed by streaking a Simmons Citrate slant with an inoculating loop. The loop was flamed and a collection of bacteria from the pure culture of unknown number 25 followed. The citrate slant was then inoculated by lightly moving the tube in a swivel pattern to help the loop not touch the walls of the container. The Citrate slant was then incubated for 48 hours in a hot room of 37 degrees Celsius. Observations of any change or growth were properly recoded
The unknown bacteria which I selected was number 25. The citrate test truly helped confirm that the unknown bacteria 25 was in fact Escherichia coli. After these experimentation my original guess was correct in saying I believed the unknown bacteria I had was E.coli, and indeed it was. E.coli is a member of the Enterobacteriaceae family which is also where Salmonella typhinurium is also classified. E.coli lives in the intestines of humans and can cause many infections ranging in severity. It doesn 't even require any growth factors, and can synthesize all essential purines, pyrimidines, amino acids and vitamins, starting with their carbon source, as part of their own intermediary metabolism (Todar). I was nervous about working with E.coli and bacteria because in general before starting this lab because of some of the symptoms they can cause. Especially intestinal swelling (MedLineplus). Even with that stated I have grown to enjoy this experiment and have learned so much valuable information that will benefit me in my nursing