Please answer the question in the picture. forming a coagulase test? Hat 1s the
ID: 3166251 • Letter: P
Question
Please answer the question in the picture.
forming a coagulase test? Hat 1s the additional information you need before per- QUESTIONS L. Why is mannitol salt agar used as a selective medium for normal skin microbiota? 2. List three identifying characteristics of Staphylococcus aureus. 3. List three factors that protect the skin from infection. CRITICAL THINKING 1. What is coagulase? How is it related to pathogenicity? Assume that you isolated S. aureus from your skin. How would you determine whether it is penicillin- resistant? 2. hip or leg. His temperature was 38°'C. A bone scan revealed damage to the head of the femur: Bacterial cultures of blood and fluid from the hip joint were positive for a gram-positive, catalase-positive, coagulase-positive cocci 3. An 8-year-old boy went to the pediatrician complaining of pain in his right hip. He had no previous injury to the that ferment mannitol. Identify the species of this bacterium.Explanation / Answer
1. Mannitol salt agar is used as a selective medium for normal skin microbiota because the normal microbiota of the skin consists of microbes which are salt tolerant. Mannitol salt agar contains 7.5% salt concentration and therefore allows only the growth of microbes which are salt tolerant i.e. the skin microbiota for example, Staphylococcus epidermitis.
2. three identifying characteristics of Staphylococcus aureus are: Gram positive, mannitol fermenting, coagulase positive.
3. Three factors which protect the skin form infection are: dry layer of epidermis, sebum and high salt concentration (hypertonic environment).
1. Coagulase is an enzyme that clots the fibrins in the blood. Cogulase is related to pathogenecity because Staphylococcus aureus posseses cell bound coagulase which can be used by the bacteria to coat its surface with fbrin. This will make the bacteria resistant to host defenses and escape phagocytosis.
2. Disk diffusion test can be used to determine if Staphylococcus aureus isolated from the skin is penicllin resistant.
3. Staphylococcus aureus