Page 171 - MNU-PM502- Pharmaeutical Microbiology Theoritical Book

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

Agar dilution

• Incorporation of dilutions of antimicrobial agent in melted media

• using serial two-fold dilutions,

• One concentration of antibiotic/ plate

• followed by the inoculation of a defined microbial inoculum on to the agar plate
surface.

• MIC endpoint is recorded as the lowest concentration of antimicrobial gent that
completely inhibits growth under suitable incubation conditions

• Agar dilution method is often preferred to broth dilution in the following
situations

➢ Multiple isolates are being tested against a single compound

➢ If the compound (or extract) tested masks the detection of microbial growth
in the liquid medium with its coloring.

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