Ch 83: Basic Principles of Antimicrobial Therapy

Question 1

What is an example of an antibiotic which can cause hemolysis in patients with deficiency of glucose-6-phosphate dehydrogenase?

Answer 1

Sulfonamides

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Question 2

What is the definition of the minimum inhibitory concentration? (MIC)

Answer 2

the lowest concentration of antibiotic that produces complete inhibition of bacterial growth (but does not KILL bacteria)

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Question 3

What is the definition of the minimum bactericidal concentration?

Answer 3

The lowest concentration of drug that produces a 99.9% decline in the number of bacterial colonies.

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Question 4

What is PCR and how does it work?

Answer 4

PCR is the polymerase chain reaction test, and it is used to detect very low titers of bacteria and viruses.
Testing is done by using either DNA or RNA polymerase, which generates thousands of copies of DNA or RNA unique to the infecting microbe. This creates enough material to detect its identity.

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Question 5

What microbes can be identified by PCR?

Answer 5

Bacteria:
Clostridium difficile, Staphylococcus aureus, Mycobacterium tuberculosis, Neisseria gonorrhoeae, Chlamydia trachomatis, Helicobacter pylori
Viruses: HIV, Influenza

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Question 6

In contaminated surgery, use of antibiotics is considered…

Answer 6

…treatment, not prophylaxis.

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