Mueller-Hinton Agar with 2% Sodium Chloride (25ml)

Approved by the National Committee for Clinical Laboratory Standards (NCCLS) in USA this medium is approved for use in antimicrobial sensitivity testing by the disc diffusion method and is recommended particularly for use with the Bauer-Kirby Technique It is low in Thymine and Thymidine and is therefore suitable for use in testing Sulphonamides & Trimethoprim and controlled to ensure correct zone sizes with Tetracyline and Aminoglycoside antibiotics. It can be considered as an alternative to Iso-Sensitest Agar. This particular formulation has an additional 2% Sodium Chloride added to the medium making it suitable for the detection of resistance to Methicillin in staphylococci and it is included in the recommendations of British Society for Antimicrobial Chemotherapy (BSAC) for this purpose. It is not however recommended for testing of organisms requiring a CO2 enriched environment due to the pH effect on the medium. If incubation in a CO2 enriched environment is essential control organisms should be included to confirm that results have not been altered.