Device for determining antimicrobial susceptibility of a microorganism
Inventors
Jarvius, Jonas • Grawe, Jan • Molin, Ylva • Klintstedt, Markus • Gullberg, Mats
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-12203125-B2
Publication Date
2025-01-21
Expiration Date
Abstract
The present invention provides methods for determining the antimicrobial susceptibility of a microorganism in a clinical sample said method comprising removing a test aliquot from a clinical sample culture before the culture reaches 0.5 McFarland units, isolating the microbial cells and transferring the cells into a suitable culture medium for microbial growth, and performing an AST assay using the isolated microbes, wherein the concentration of microbial cells in the microbial cells used to set up the AST assay is measured before the degree of microbial growth in the different growth conditions of the AST assay is measured. Devices for determining the antimicrobial susceptibility of a microorganism in a clinical sample are also provided.
Core Innovation
The invention relates to a rapid antimicrobial susceptibility testing (AST) workflow and a corresponding device for determining antimicrobial susceptibility of a microorganism in a clinical sample. The workflow isolates microbial cells from the clinical sample by selectively lysing non-microbial cells using a lysis buffer, then filtering to retain bacteria and using a wash reservoir with culture medium to back-flush the filter and resuspend the microbial cells into a microbial culture preparation.
The workflow then inoculates a series of test microbial cultures for antibiotic susceptibility testing. A measurement unit determines concentration of microbial cells and assesses the degree of microbial growth in the series of test microbial cultures, and the measurement unit includes a concentration determination unit and a separate assessment unit, each comprising a camera.
The controller controls the measurement unit to measure microbial-cell concentration in the microbial culture preparation and/or in the test microbial cultures, and controls the device to adjust the concentration of microbial cells in the microbial culture preparation and/or the test microbial cultures to a desired or pre-determined concentration. Based on the assessed degree of microbial growth, the controller determines at least one minimum inhibitory concentration (MIC) value for at least one antimicrobial agent, thereby determining antimicrobial susceptibility for the microorganism from the clinical sample.
Claims Coverage
The independent claims define a complete AST device architecture with selective lysis-based isolation, inoculation of test microbial cultures, camera-based concentration determination and separate growth assessment, controller-driven concentration adjustment, and MIC determination. Across the independent claims, the inventive features are selective isolation of microbial cells, camera-based concentration and growth measurement, concentration adjustment, and MIC determination from assessed growth degree.
Selective isolation of microbial cells using selective lysis, filtration, and back-flushing
An isolation unit for isolating microbial cells from the clinical sample, including a lysis reservoir, a reservoir containing a lysis buffer capable of selectively lysing non-microbial cells, a filter configured to retain bacteria after lysis, and a wash reservoir containing a culture medium for back-flushing the filter to resuspend the microbial cells and prepare a microbial culture preparation.
Inoculating test microbial cultures for antibiotic susceptibility testing
An inoculation unit configured to inoculate a series of test microbial cultures taken from a microbial culture preparation for an AST.
Camera-based concentration determination and separate growth assessment
A measurement unit for determining concentration of microbial cells and for assessing the degree of microbial growth in the series of test microbial cultures, including a concentration determination unit for determining concentration in the microbial culture preparation and a separate assessment unit for assessing growth, wherein both units comprise a camera.
Controller-controlled microbial concentration adjustment to a desired or pre-determined concentration
A controller configured to control the device to adjust the concentration of microbial cells in the microbial culture preparation and/or the test microbial cultures to a desired or pre-determined concentration.
MIC determination from assessed degree of microbial growth
Based on the assessed degree of microbial growth, determine at least one minimum inhibitory concentration (MIC) value for at least one antimicrobial agent, thereby determining antimicrobial susceptibility of the microorganism in the clinical sample.
The independent claims combine selective lysis-based isolation and wash/back-flushing preparation, inoculation of a series of test microbial cultures for AST, camera-based concentration determination with a separate growth assessment unit, controller-controlled adjustment of microbial concentration, and MIC determination using the assessed degree of microbial growth.
Stated Advantages
Eliminates the conventional requirement to grow cultures to 0.5 McFarland/positive status, enabling earlier results.
Enables use of non-standard starting titers with concentration-aware interpretation of MICs.
Provides correlation and reproducibility between imaging-derived MIC and reference methods.
Documented Applications
Determining antimicrobial susceptibility (AST) of clinical bacterial isolates by deriving MIC values from camera-based concentration measurement and growth assessment in test microbial cultures.
Testing clinical isolates with dependence on initial microbial concentration, and correlating imaging-derived MIC with reference methods.
Interested in licensing this patent?