Abstract:
Intro
Staphylococcus aureus is a facultative anaerobic gram positive bacterium, known to cause skin infection, respiratory disease and food poisoning. It causes infections by producing potent protein toxins and expressing cell-surface proteins that inactivates antibodies. In clinical medicine, the emergence of antibiotic-resistant forms of S. aureus (e.g. MRSA) is a global pathogenic issue. Physiological and genetic differentiation are important for bacterial identification and cellular process understanding. Because genes are recipes for making cellular proteins, including the enzymes that regulate the cell metabolism. Therefore, species with similar enzymatic capabilities are more likely to have similar genetic makeup.
Methods
According to bacterial differential, selective and complex media, growth characteristics were visualized by incubating MSA, EMB and TSA plates at 37°C for 48 hours, Furthermore, bacterial physiological test helped support the organism metabolic capabilities…show more content… The tubes are incubated at 37 degrees for 24‐48 hours. If negative results, slant need to be re-incubated for another 5 days.
Nitrate Reduction: use of a nitrate broth to inoculate the organism with an inoculating loop, incubate for 48 hours at 37°C. Then, 5 drops of nitrate solution A and B are added to the tube to observe for red color change. If no red color is developed, a small amount of Zinc is recommended for the color change.
Catalase [TSA plate]: inoculate TSA plate by streaking each half of the plate with a loop full of culture. Incubate plate for 48 hours at 37°C then add 3-4 drops of H2O2 to one half of the growth to observe for bubbles. Alternatively, a cotton tip swab of growth can be removed and applied to a filter paper, and procedure is repeated according to protocol.
