• Home |
• Contacts |
• Quality Standards |
• Instructions for Use |
• Careers

• Anaerobic Systems
• Antibiotic Sensitivity Testing
• • Are there any general guidelines for carrying out AST by disc diffusion?
  • How should I interpret antibiotic disc zone sizes?
  • How should I store antibiotic discs?
• Culture Media, Supplements and Raw Materials
• Diagnostic Reagents
• Dipslides
• General
• Toxin Detection

OXOID TECHNICAL SUPPORT DEPARTMENT GUIDELINES

ANTIBIOTIC DISC INTERPRETIVE CRITERIA

Antibiotic discs manufactured by Oxoid may be used within a variety of antibiotic sensitivity testing methods and protocols. Zone diameters will vary depending upon the method used and are influenced by factors such as: medium used, depth of agar and inoculum density.

Zone diameter interpretive criteria (SIR) only have relevance, therefore, when applied to a standardised testing method defined by a standards organisation e.g. the National Committee for Clinical Laboratory Standards (NCCLS) or British Society for Antimicrobial Chemotherapy (BSAC). Interpretive criteria are defined and published by the standard body and are established by the collation of a large amount of actual testing data.

Oxoid cannot generally provide zone interpretive criteria. If a customer is following a standard method, then interpretive criteria may be obtained through the standard body. If a customer is not currently following a recognised testing protocol, then the antibiotic manufacturer may be contacted for their advice. Manufacturer information may be found on the packaging of the therapeutic antibiotic.

Useful websites:
www.nccls.org
www.bsac.org.uk