Exam 13: Antimicrobial Susceptibility Testing

As a general guideline,it is suggested that within a particular antimicrobial class,primary (group A)agents be reported first and secondary (group B)agents be reported only if:

Oxacillin-resistant Staphylococcus aureus is called:

The broth microdilution minimal inhibitory concentration (MIC)test uses these for the testing.

Spontaneous mutations occur in the b-lactamase genes that result in extended-spectrum β-lactamases (ESBL).These ESBL inactivate:

What broth is recommended in the tube dilution minimal inhibitory concentration (MIC)tests?

A combination of antimicrobials is said to show synergism if:

Many times,antimicrobial susceptibility testing includes drugs that are inappropriate for reporting.What does the technician do?

What type of antimicrobial susceptibility testing method does Clinical and Laboratory Standards Institute (CLSI)recommend for anaerobes?

A patient is admitted to the hospital with a diagnosis of endocarditis.Two separate blood cultures grow out viridans streptococci.The penicillin minimal inhibitory concentration (MIC)of the organism is 0.12 µg/mL.What antibiotic should the physician prescribe?

Why should antimicrobial susceptibility testing of normal flora isolates or isolates likely to represent contamination or colonization not be performed?

Quality control of antimicrobial susceptibility tests involves:

What is generated by analysis of individual susceptibility results on isolates from a particular institution in a defined period and represents the percentage of isolates of a given species that is susceptible to the antimicrobial agents commonly tested against the species?

Why would normal flora isolates from immunosuppressed patients undergo antimicrobial susceptibility testing?

The minimum bactericidal concentration (MBC)test differs from the minimal inhibitory concentration (MIC)test because the MIC test gives the concentration needed at the site of infection to inhibit bacterial multiplications,whereas the MBC gives:

Why are aminoglycosides not an effective treatment for meningitis?

How long are minimal inhibitory concentration (MIC)panels for anaerobes incubated?

If the minimal inhibitory concentration (MIC)or zone size is interpreted as resistant using the latest Clinical and Laboratory Standards Institute (CLSI)tables:

What McFarland standard provides turbidity comparable to that of a bacterial suspension containing approximately 1.5 ´ 10⁸ CFU/mL?

All of the following techniques are used to measure the amount of antimicrobial agent in the serum EXCEPT:

Who sets the criteria in the table of values that relates the diameter of the zone to a category of susceptibility in disk diffusion testing?