Regulatory-aligned MIC testing and AMR interpretation for microbial safety assessment
Minimum inhibitory concentration (MIC) testing is a key component of antimicrobial resistance (AMR) assessment for microbial production strains. BaseClear performs standardized MIC testing to determine the susceptibility of microorganisms to clinically relevant antimicrobials. These data are essential to evaluate whether a strain exhibits resistance and to support safety assessment in regulatory submissions.
This service is intended for companies developing microbial products such as food enzymes, feed additives, probiotics, and novel foods. It is particularly relevant for applicants preparing dossiers for EFSA and other regulatory authorities, where phenotypic AMR data are required to complement genomic analysis and demonstrate the absence of acquired resistance.
MIC testing is performed using standardized broth microdilution methods in accordance with CLSI guidelines. A panel of antimicrobials relevant to human and veterinary medicine is selected based on EFSA FEEDAP recommendations. Quality control strains are included to ensure assay validity. Results are interpreted against established cut-off values, and deviations are assessed in the context of intrinsic resistance and methodological variability.
Clients receive a comprehensive, regulatory-ready report including MIC values, quality control results, and detailed interpretation aligned with EFSA expectations. Integrated with WGS analysis, the report enables clear differentiation between intrinsic and acquired resistance and provides justified interpretation of any deviations from reference ranges. All data are formatted for direct inclusion in regulatory dossiers, minimizing the need for further clarification.
We assess whether the test strain can be cultivated under standard MIC conditions. Where necessary, conditions are adapted to ensure valid and reproducible susceptibility testing.
We define the antimicrobial panel and testing strategy based on regulatory requirements and strain type.
Your strain is tested using standardized broth microdilution assays under controlled laboratory conditions.
Quality control strains and acceptance criteria are applied to ensure data reliability and compliance.
Results are interpreted in line with EFSA guidance, including assessment of intrinsic versus acquired resistance.
MIC testing performed according to CLSI standards
Integrated wet-lab and bioinformatics workflows
Expertise in distinguishing intrinsic versus acquired resistance
Clear, dossier-ready reporting to support regulatory submissions
Minimum inhibitory concentration (MIC) testing determines the lowest concentration of an antimicrobial that inhibits visible growth of a microorganism. It is required to assess whether a production strain exhibits resistance to clinically relevant antimicrobials, which is a key safety concern in regulatory evaluations.
MIC testing is typically performed according to CLSI standards such as M07 and M45. These standardized methods ensure reproducibility and comparability of results and are accepted by regulatory authorities.
MIC results are interpreted by comparing measured values to established cut-off thresholds, such as EFSA cut-offs. Values above the cut-off may indicate acquired antimicrobial resistance and require further investigation and justification.
Intrinsic resistance is a natural, species-specific characteristic, while acquired resistance results from genetic changes such as mutations or horizontal gene transfer. Regulatory concern focuses on acquired resistance, as it may be transferable and pose a risk to human or animal health.
A one two-fold dilution difference from reference values is generally considered within acceptable experimental variation. However, results exceeding regulatory cut-offs must be carefully evaluated, including consideration of method performance, strain variability, and supporting genomic data.
MIC testing alone is not sufficient to fully assess antimicrobial resistance risk. A comprehensive evaluation requires integration of phenotypic MIC results with genomic analysis, including identification of resistance genes and assessment of their relevance.
Genomic analysis to identify antimicrobial resistance genes and support
Evaluation of biologically active metabolites to assess functional and toxicological risks
Demonstration of absence of viable cells and recombinant DNA in final products for regulatory compliance
Integration of MIC, genomic, and safety data into a submission-ready regulatory dossier
Get expert guidance on MIC testing, interpretation, and regulatory strategy to avoid delays in your submission. Start with a free consultation tailored to your project.
