Microbiology Fundamentals: A Clinical Approach
3rd Edition
ISBN: 9781259709227
Author: Marjorie Kelly Cowan Professor, Heidi Smith
Publisher: McGraw-Hill Education
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Textbook Question
Chapter 15, Problem 11Q
You perform a Kirby-Bauer disk diffusion test to determine antibiotic susceptibilities of a clinical isolate. There is a clear zone of several millimeters around the penicillin disk, but there are two to three distinct colonies in the middle of the clear halo. What is the probable explanation for those colonies?
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Suppose you do the Kirby-Bauer test on a hypothetical Staphylococcus species with penicillin and tetracycline. You record diameters of 20mm for tetracycline and 24mm for penicillin. Which antibiotic is most effective against this bacterium and why? Please explain and interpret these results.
In the Kirby-Bauer test, which of the following must be consistent?
a. concentration of bacteria placed on the plate
b. type of medium in the plate
c. concentration of antimicrobial drug in the disk
d. all of these
Suppose you do this test on a hypothetical Staphylococcal species with the antibiotics penicillin and tetracycline. You record zone diameters of 20mm for the tetracycline disc and 25mm for the penicillin disc. Which antibiotic would be most effective against this organism? What does this tell you about comparing zone diameters to each other and the importance of the interpretive chart?
Chapter 15 Solutions
Microbiology Fundamentals: A Clinical Approach
Ch. 15.1 - Prob. 1AYPCh. 15.1 - Provide a one-sentence description for each of...Ch. 15.2 - Identify factors that may affect the...Ch. 15.2 - Prob. 4AYPCh. 15.2 - NCLEX PREX 1. An RN is training a new staff nurse...Ch. 15.2 - NCLEX PREX 2. A clinical form used to report data...Ch. 15.3 - List at least three different tests that fall in...Ch. 15.3 - Prob. 6AYPCh. 15.3 - Discuss two major drawbacks of phenotypic testing...Ch. 15.3 - Q. What technique in this chapter do most home...
Ch. 15.3 - NCLEX PREX 3. When determining the clinical...Ch. 15.4 - Define the term serology, and explain the...Ch. 15.4 - Identify two immunological diagnostic techniques...Ch. 15.4 - Prob. 2MMCh. 15.5 - Explain why PCR is useful for infectious disease...Ch. 15.5 - Name two examples of techniques that employ...Ch. 15.5 - Explain how whole-genome sequencing can be used...Ch. 15.5 - Prob. 13AYPCh. 15.5 - Prob. 3MMCh. 15.6 - Describe the benefits of lab on a chip...Ch. 15.6 - Prob. 15AYPCh. 15 - When using pulsed-field gel electrophoresis,...Ch. 15 - Explain why it is possible to identify some...Ch. 15 - Serotyping identifies distinct members of the same...Ch. 15 - Prob. 4QCh. 15 - Name some bacterial structures that might be...Ch. 15 - You perform a lumbar puncture on a patient with...Ch. 15 - Which category of diagnosis is represented by...Ch. 15 - Write a paragraph that explains the mycobacterial...Ch. 15 - You inoculated a biochemical test strip with a...Ch. 15 - Prob. 10QCh. 15 - You perform a Kirby-Bauer disk diffusion test to...Ch. 15 - Why might culture conditions affect the results of...Ch. 15 - Which of the following techniques is most likely...Ch. 15 - Why is it more important to use selective media...Ch. 15 - What type of diagnostic method do you think would...Ch. 15 - T or F: Bacterial infection causes the expression...Ch. 15 - Prob. 17QCh. 15 - Prob. 18QCh. 15 - Prob. 19QCh. 15 - When PCR is performed by hand (not with a...Ch. 15 - What kind of a control would be important to run...
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