BIOS 242 Week 6 Lab 2; Bacteria of Respiratory System

Lab 12: Bacteria of the Respiratory System Introduction: The respiratory system is divided into two parts: the upper and lower respiratory systems. The lower respiratory system is an axenic environment because of the cilia that lines the respiratory tract, alveolar macrophages and IgA antibodies found in the mucus. The upper part harbors a variety of microbiota such as Gram-negative bacteria Hemophilus, Gram-positive bacteria such as Staphylococcus aureus and diphtheroids that can cause opportunistic infections leading to infection like pneumonia and diphtheria……. Continue 1. Alpha hemolysis: 2. Beta hemolysis: 3. Gamma hemolysis: Materials: Liquid cultures of B. subtilis, E. coli, S. epidermidis and S. marcescens, BAP plates, Incinerators, Metal loops Method: 1. Obtain liquid cultures of S. epidermidis, E. coli, B. subtilis and S. marcescens as well as two BAP plates per group of four students. 2. Take one BAP plate and divide it in three parts. 3. Label each part correctly with the name of the bacteria. Leave the third area empty. 4. Take second BAP plate and divide it in three parts. 5. Label each part correctly with the name of the bacteria. Leave the third area empty. 6. Using aseptic culture transfer techniques, streak the cultures on BAP plates. 7. Let the cultures grow overnight at 370C. 8. Observe the growth and complete Lab Report. Purpose: Describe the purpose of this lab. 1. Is blood agar selective or differential? Briefly explain. 2. Is the Gram stain of significant importance in identifying the organisms studied in this exercise? Explain. 3. List some diseases of upper respiratory system that you learned in lecture that can help you identify the causative microorganism using BAP plates. Observation: Complete the following table. Obtain the results of Gram reaction, morphology and arrangement from labs 4 and 5. Review literature to find reaction of S. aureus.