Explain what is meant by “indicator” organisms when testing a water sample.


Explain what is meant by “indicator” organisms when testing a water sample. What are the media used to determine the presence of the indicator organisms? What are the morphological and biochemical characteristics of these indicator organisms?Discuss the three major species of Staphylococcus. Explain why one of them is more pathogenic compared to the other two species. Which factor determines the pathogenesis of the organisms?

Document Preview:

BIO2071_Microbiology Laboratory Review Sheet Week 10 Exercise 11 Questions 1. In what areas of the hospital must the numbers of microorganisms in the environment be strictly reduced to the minimum? 2. Why do microbiologists wear laboratory coats? Did you confirm that this is necessary? 3. Why is it necessary to wear clean, protective clothing when caring for a patient? 4. Why should hair be kept clean and out of the way when caring for patients? 5. How can the number of microorganisms in the environment be controlled? 6. When and why is hand washing important in patient care? 7. How can those who care for patients avoid spreading microorganisms among them? Exercise 20.1 and 20.2 Questions 1. Differentiate the microscopic morphology of staphylococci and streptococci as seen by Gram stain. 2. What are the two types of staphylococcal coagulase? 3. What is protein A? Describe one method of detecting it. 4. What properties of S. aureus distinguish it from S. epidermidis and S. saprophyticus? 5. How is S. saprophyticus distinguished from S. epidermidis? 6. From what specimen type would S. saprophyticus most likely be isolated? 7. What is a nosocomial infection? Who acquires it? Why? 8. Why are staphylococcal infections frequent among hospital patients? 9. Describe the role played by S. aureus in human infectious diseases. Page 1 of 2 From Laboratory Manual & Workbook in Microbiology Applications to Patient Care (9th ed.). By Josephine A. Morello, Helen Eckel Mizer, and Paul A. Granato Copyright © 2006 The McGraw-Hill Companies, Inc. Reprinted with permission of The McGraw-Hill Companies, Inc.

BIO2071_Microbiology Laboratory Exercise 34 Questions 1. What is the bacteriologic standard for potable water? 2. Why is bacteriologic analysis of water directed at recognition of coliforms and enterococci rather than isolation of pathogenic bacteria? 3. Define presumptive, confirmed, and completed tests of water. 4. Why must positive presumptive tests of water be confirmed? 5. In…