Page 163 - MNU-PM502- Pharmaeutical Microbiology Theoritical Book

Pharm D- Clinical Pharmacy Program Third Level Pharmaceutical Microbiology& Antimicrobials (PM 502)

Antimicrobial Susceptibility Testing

Antibiotic sensitivity test: A laboratory test which determines how effective
antibiotic therapy is against a bacterial infection.

• Antibiogram provides qualitative results by categorizing bacteria as susceptible,
intermediate or resistant

• Antibiotic sensitivity testing will control the use of Antibiotics in clinical

practice

• Susceptible: the microorganism is inhibited by a concentration of
antimicrobial agent at the recommended dose.

• Resistant: the microorganism is resistant to concentrations of the
antimicrobial agent and an infection caused by this microorganism could not be

treated with this antimicrobial agent

Why do we test antimicrobial susceptibility?

• To direct & predict appropriate antimicrobial treatment.

• Surveillance of resistance in community and hospital out
breaks.

• Formulation of national & local antibiotic policies.

• To test the activity of a new antimicrobial agent.

• To presumptively identify isolates.

But remember…

• Other factors are very important when we choose an antibiotic

- Will it get to where the infection is?
- Bioavailability
- Cost
- Toxicity
- Likelihood of development of resistance, Etc…

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