The purpose of this study is to study the morphology and to be able to distinguish between nine types of bacteria, which include: Staphylococcus epidermis, Micrococcus luteus, Bacillus cereus, Corynebacterium xerosis, Mycobacterium phlei, Proteus mirabilis, Escherichia coli, Klebsiella oxytoca and Sarcina flava. .
MATERIALS AND METHODS:.
Standard lab procedures were used in this study. Tests performed include: The Gram Stain to study the gram reaction and morphology; the Nigrosine Stain (Negative) used to test for a capsule and confirm morphology; the Loeffler Methylene Blue Test to test for metachromatic granules; the Shaeffer-Fulton Test used to check for spore formation; the Ziehl-Neelson Acid Fast Test to test for the presence of mycolic acid; the SIM motility test to test motility and check for the presence of H2S; slant test for pigmentation and also a broth test for its characteristics. .
Refer to attached flow chart.
DISCUSSION OF RESULTS:.
The Gram Stain was first performed showing the unknown to be gram negative. The slide also showed the bacteria to be bacillis shaped. Six gram positive bacteria were therefore eliminated, including Staphylococcus epidermis, Micrococcus luteus, Bacillus cereus, Corynebacterium, Mycobacterium phlei and Sarcina flava. Next the Negative stain was performed using nigrosine to confirm the morphology and show the presence of a capsule in the unknown; the morphology results were consistent with the gram stain. Here another bacteria was eliminated as the unknown due to the lack of a capsule; that being Proteus mirabilis. At this point the only possibilities left were Escherichia coli and Klebsiella oxytoca. To conclude what the unknown was a SIM motility test was done, which proved to be positive. Therefore Klebsiella oxytoca was eliminated and my unknown was presumably Escherichia coli. In order to confirm my results the slant growth and broth characteristics were tested.