In antibiotic susceptibility testing, what does 'Intermediate' mean?

In antibiotic susceptibility testing, what does 'Intermediate' mean?

• A. Drug should only be used if no other option is available
• B. The organism is highly susceptible
• C. The drug is always ineffective
• D. The test cannot determine susceptibility

Answer: (A)

Intermediates indicate a caution zone in antibiotic effectiveness. The drug may work, but not reliably at standard dosing. It can be effective if higher doses can be used or if the infection site concentrates the drug, making the outcome more situational than clearly susceptible. Because of this nuance, clinicians often reserve such drugs for situations where no better options exist or where dosing strategies and site-specific factors can achieve the needed levels. This aligns with the idea that the drug should be used only if no other option is available. The other descriptions aren’t accurate: being highly susceptible means reliable effectiveness at standard doses; saying it’s always ineffective describes resistance; and the test does provide a readout that includes an intermediate category, not an indeterminate result.

Intermediates indicate a caution zone in antibiotic effectiveness. The drug may work, but not reliably at standard dosing. It can be effective if higher doses can be used or if the infection site concentrates the drug, making the outcome more situational than clearly susceptible. Because of this nuance, clinicians often reserve such drugs for situations where no better options exist or where dosing strategies and site-specific factors can achieve the needed levels.

This aligns with the idea that the drug should be used only if no other option is available. The other descriptions aren’t accurate: being highly susceptible means reliable effectiveness at standard doses; saying it’s always ineffective describes resistance; and the test does provide a readout that includes an intermediate category, not an indeterminate result.