What is ISO 20776‑1 about?
ISO 20776 discusses susceptibility testing of infectious agents and evaluation of the performance of antimicrobial susceptibility test devices. ISO 20776‑1 describes one reference method, broth microdilution, for the determination of minimum inhibitory concentrations (MICs).
The MIC can be a guide for the clinician and reflects the activity of the drug under the described test conditions, by considering other factors, such as drug pharmacology, pharmacokinetics, or bacterial resistance mechanisms. This allows the categorisation of bacteria as “susceptible” (S), “intermediate” (I), or “resistant” (R). MIC distributions can be also used to define the wild-type or non-wild-type bacterial populations.
Note: ISO 20776‑1 may involve hazardous materials, operations, and equipment. ISO 20776‑1 does not purport to address all the safety problems associated with its use. It is the responsibility of the user of ISO 20776‑1 to establish appropriate safety and health practices and to determine the applicability of any other restrictions before use.
Who is ISO 20776‑1 for?
ISO 20776‑1 on broth microdilution for MIC distribution determination is useful for:
- Microbiologists
- Pharmaceutical researchers
- Biomedical laboratories
- Regulatory authorities
Why should you use ISO 20776‑1?
Broth microdilution is a method used to test the susceptibility of microorganisms to antibiotics. In vitro antimicrobial susceptibility tests are performed on microorganisms suspected of causing disease, if the organism is thought to belong to a species that may exhibit resistance to frequently used antimicrobial agents. The tests are also important in resistance surveillance, epidemiological studies of susceptibility, and comparisons of new and existing agents for in vitro activity of antimicrobial agents.
ISO 20776‑1 guidelines help you with the preparation of stock solutions, working solutions, micro-dilution trays, and storage of micro-dilution trays for the determination of MICs. ISO 20776‑1 provides the broth microdilution culture method and direct colony suspension method for the assessment.
What’s changed since the last update?
BS EN ISO 20776‑1:2020 supersedes ISO 20776‑1:2006, which has been withdrawn. BS EN ISO 20776‑1:2020 has some technical change with respect to ISO 20776‑1:2006. These include:
- Revised to a broth micro-dilution only performance document
- Removal of S, I, R breakpoint definitions and information
- Moved embedded tables to annexes
- Updated table (now Annex B) on solvents and diluents for antimicrobial agents used globally
- Updated information on special culture media and method performance for specific currently used antimicrobial agents