Staphylococcus aureus biological characteristics
Biological characteristics 1. Form and color Gram-positive cocci without capsules. Arranged in a grape shape. Pathogenic cocci are relatively small, with a diameter of about 0.5 microns. 2. Culture characteristics Low nutritional requirements, good growth on common medium, facultative anaerobic, optimal growth temperature 37 degrees, strong salt tolerance can grow in 10-15% sodium chloride medium, 37 in broth medium After 24 hours of incubation, it grew uniformly and turbidly. After prolonging the cultivation time, a small amount of precipitate appeared at the bottom of the tube. After cultivating on nutrient agar medium for 24-48 hours, colonies with rounded convex edges, smooth surfaces, moist and opaque surfaces were formed, with a diameter of 1-2 microns. The pathogenic Staphylococcus aureus produces a hemolytic circle around the colony due to the production of hemolysin 3. Biochemical characteristics (see textbook) 4. Toxins and enzymes (1) can produce hemolysin, causing red blood cells to dissolve to produce hemolytic rings or hemolytic circles. (2) The production of enterotoxin is a soluble protein. It cannot be destroyed at 100 degrees for 30 minutes. It takes 100 degrees for 2 hours to completely destroy it. It can cause acute gastroenteritis in people. (3) Lecithinase is grown on the yolk plate, there is a turbid zone around the colony, and there is a transparent circle outside. (4) Producing coagulase, which turns prothrombin in plasma into plasma coagulase, and coagulates plasma. EVA Raincoat, Kids EVA Raincoat, Childrens EVA Raincoat, EVA Raincoat For Kids
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