Total laboratory automation-based monitoring processes: setup and validation of an integrated internal quality...

Total laboratory automation (TLA) is now widely implemented in diagnostic microbiology laboratories. However, a coherent and standardized quality surveillance procedure for all the automated culture-based processes is currently lacking.

We set up and implemented an internal quality control (IQC) panel to assess the automated culture-based processes and workflows.

A subset of reference strains was applied to monitor liquid and solid culture media used in all culture-based processes on the TLA. This integrated IQC panel monitors staining, automated plate streaking, incubation and digital imaging, artificial intelligence (AI)-assisted plate reading, identification by MALDI-ToF-MS, fully automated antimicrobial disc diffusion susceptibility testing, minimum inhibitory concentration (MIC) determination by broth microdilution and E-test strips, and finally, detection of the defined antimicrobial resistance genes by molecular assays.

During 6 months of implementation of this new routine IQC approach, no errors were detected regarding all the culture-based and antimicrobial susceptibility testing (AST) processes, including antimicrobial resistance gene detection, with the exception of one major error related to a MIC misreading for imipenem.

This IQC approach ensures the traceability and control of the analytical phase of an automated laboratory. Annual costs for these integrated IQC panels amounted to CHF 17,886.-, of which 53% were related to personal time costs. The latter could be improved by further software development for sample prescription, data collection, and reporting.