Sticky Test

Decent Essays

The proposed identity of the unknown organism is Staphylococcus hyicus subspecies chromogenes though, due to variability of results for the specie strains, the unknown organism may also be Staphylococcus haemolyticus. All test results were consistent with my partner’s and other groups who had the same unknown organism. No test results contradicted the physiological concept of another test.
An elimination genus tree was used to determine the unknown organism’s genera. Gram negative Escherichia, Pseudomonas, and Serratia were eliminated as the possible genera of the unknown organism. (1) The gram characteristic of the unknown organism was determined with gram staining, absence of growth on MacConkey media, and negative result for the Sticky test. The unknown organism was gram stained purple, which was the same stain for Staphylococcus epidermidis, the gram positive …show more content…

Tests used in the species elimination tree were cytochrome C, sucrose, mannitol and lactose fermentation, acetoin production, and urease. Species that were 11-89% positive for a test were not eliminated. The unknown organism was negative for cytochrome C, which eliminated the cytochrome C positive S. caseolyticus, S. sciuri, and S. lentus. The organism was positive for sucrose fermentation, which eliminated S. sacchrolyticus, S. cohnii, S. carnosus, and S. caprae. Mannitol fermentation eliminated mannitol negative S. epidermidis, S. hominis, S. aurialaris, and S. hyicus hyicus. The unknown organism was negative for urea hydrolysis so 7 species were eliminated and S. capitis, S. haemolyticus, and S. hyicus chromogenes remained. Lactose fermentation eliminated S. capitis. The unknown organism was able to degrade gelatin so the gelatin negative S. haemolyticus was eliminated and positive S. hyicus chromogenes remained as the identity of the unknown.

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