What does bactericidal mean? Bacteriostatic? Virucidal? Fungistatic?

25 Jun What does bactericidal mean? Bacteriostatic? Virucidal? Fungistatic?

Question
BIO2071 Microbiology Laboratory Week 10
Week 10 Review Sheet I

Exercise 1 – Disinfectants

1. What does bactericidal mean? Bacteriostatic? Virucidal? Fungistatic?

2. Why are control cultures necessary in evaluating disinfectants?

3. What factors can influence the activity of a disinfectant?

4. Why do microorganisms differ in their response to disinfectants?

5. What microorganisms are most susceptible to disinfectants?

EXERCISE 2 – Antimicrobial Agent Susceptibility Testing and Resistance

1. What is meant by antimicrobial resistance? Susceptibility?

2. Why are pure cultures used for antimicrobial susceptibility testing?

3. Would it be acceptable to use a mixed culture for this test? Why?

4. List three factors that can influence the accuracy of the test.

5. When performing a broth dilution test, why is it necessary to include a growth control tube?

A sterility control tube?

EXERCISE 3 – The Enterobacteriaceae (Enteric Bacilli)

1. What does the term IMViC mean?

2. Why is the IMViC useful in identifying Enterobacteriaceae? Are further biochemical tests necessary for complete identification?

3. What diagnostic test differentiates Proteus and Providencia species from other

Enterobacteriaceae?

4. How is E. coli distinguished from P. vulgaris on MacConkey agar? On a TSI slant?

5. Why is it important to differentiate glucose nonfermenters from Enterobacteriaceae?

EXERCISE 4 – Streptococci, Pneumococci, and Enterococci

1. Differentiate the microscopic morphology of streptococci and pneumococci as seen by

Gram stain.

2. What type of hemolysis is produced by S. pneumoniae?

3. How is S. pneumoniae distinguished from other streptococci with the same hemolytic properties?

4. Describe the hemolysis produced by alpha-hemolytic, beta-hemolytic, and nonhemolytic streptococci.

5. What type of hemolysis is displayed by the groupable streptococci that are most pathogenic for human beings?

Week 10 Review Sheet II

EXERCISE 1 – Serodiagnosis of Infectious Disease

1. Define serum titer.

2. What are acute and convalescent sera? Why must both be tested to make a serological diagnosis of infectious disease?

3. What is the difference between an agglutination test and a precipitation test?

4. In a paired serum sample, what test results indicate recent infection?

5. What is a humoral antibody?

EXERCISE 2 – Culturing Microorganisms from the Environment

1. Why do microbiologists wear laboratory coats? Did you confirm that this is necessary?

2. Why is it necessary to wear clean, protective clothing when caring for a patient?

3. Why should hair be kept clean and out of the way when caring for patients?

4. How can the number of microorganisms in the environment be controlled?

5. When and why is hand washing important in patient care?

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. Page 1

BIO2071_Microbiology Laboratory

6. How can those who care for patients avoid spreading microorganisms among them?

EXERCISE 3 – Staphylococci

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. Why are staphylococcal infections frequent among hospital patients?