Measurement of cell growth and drug susceptibility by resonant mass measurement
Inventors
Babcock, Ken • Schneider, Cynthia
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-9835614-B2
Publication Date
2017-12-05
Expiration Date
Abstract
System and Method for measuring the growth of a bacterial culture and its response to one or more antimicrobials using measurement of mass of individual microbes. Methods include periodic sampling, determining change in mass and concentration, and comparing growth rates of cultures in nutrient broth vs. mixtures containing various antibiotic mixtures. A number of antimicrobials can be compared in one measurement by multiplexing or using multiple sensors to measure in parallel. Growth and antibiotic efficacy can be assessed at low concentrations at the onset of growth, typically within 1 to 2 hours.
Core Innovation
The invention relates to a method for measuring growth of cells in a fluid culture by repeatedly introducing culture portions into a microchannel at different times and detecting each cell as it passes through the microchannel. Each portion has a known fluid volume and a plurality of cells at a concentration chosen so that for a majority of the time at most one cell is present in the microchannel at a given time. The method includes at least one of counting or measuring a property of each cell passing through the microchannel at the first time and at later times.
Growth rate is calculated from at least one of the change in the count per fluid volume or the measured property between the two times. At least one agent, whose effect on the growth rate of the culture is unknown, is added to the culture, so that changes in measured concentration and/or cell property can be used to determine growth rate effects attributable to the unknown agent.
In embodiments using a panel of varying cultures, a first portion of a culture is selected from a vial, introduced into a microchannel, and cells are detected as they pass through the microchannel. The method repeats for a plurality of culture vials and later times for additional different culture portions, while calculating growth rates for cultures in each vial from changes in concentration or the measured property between the two times. The panel can include control cultures in which no growth-affecting agent is present.
Claims Coverage
The independent claims identified are clm-00001, clm-00014, and clm-00019. Across these claims, the coverage centers on microchannel-based single-cell detection with repeated time-point measurements and growth rate calculation from changes in count per fluid volume or a measured cell property, with an unknown-effect agent added to the culture(s) being measured. Claim sets further refine the culture sourcing, inclusion of controls, and timing relationships between measurements and cell replication time.
Microchannel single-cell detection with known volume portions at time points
introducing a first portion of the culture into a microchannel at a first time, the portion of culture having a known fluid volume and containing a plurality of cells at a concentration chosen that for a majority of the time at most one cell is present in the microchannel at a given time; detecting each cell as the culture passes through the microchannel; introducing at least one additional, different portion of the culture into the microchannel having a known fluid volume at at least one later time; repeating the detection steps at the later time(s)
Counting or measuring a cell property and calculating growth rate from changes between times
at least one of counting or measuring a property of each cell passing through the microchannel; calculating the growth rate in the culture from at least one of the change in the count per fluid volume or the measured property between the two times
Unknown growth-affecting agent added to the culture
wherein at least one agent, whose effect on the growth rate of the culture is unknown, is added to the culture
Panel/vial culture selection and repeated measurements across multiple cultures
selecting from a panel of vials of varying cultures a first portion of a culture from a vial; introducing the first portion of the culture into a microchannel at a first time; detecting each cell as the culture passes through the microchannel; at least one of counting or measuring a property of each cell passing through the microchannel; repeating the steps for a plurality of the culture vials in the panel; repeating the steps at least one later time for additional different culture portions having known fluid volumes; calculating the growth rates for the cultures in each vial from at least one of the change in the count per fluid volume or the measured property between the two times
Multiple cultures with microchannel assignment and parallel detection at time points
selecting from a panel of varying cultures, a first portion of each of a plurality of cultures; introducing these first portions into a plurality of microchannels at a first time, each portion of culture having a known fluid volume and containing a plurality of cells at a concentration chosen that for a majority of the time at most one cell is present in the microchannel at a given time where each microchannel accepts the portion from one of the cultures; detecting each cell in each microchannel as the cultures passes through the microchannels; at least one of counting or measuring a property of each cell passing through the microchannels; repeating the steps for additional different culture portions having known fluid volumes in the panel; repeating the steps at least one later time
Growth rate calculation from concentration or measured property changes for panel cultures
calculating the growth rates for the cultures from at least one of the change in the count per fluid volume or the measured property of each culture between the two times
Unknown growth-affecting agent added to at least one culture in the panel
wherein at least one agent, whose effect on the growth rate of the culture is unknown, is added to at least one of the cultures
Across claims clm-00001, clm-00014, and clm-00019, the patent covers growth measurement in fluid culture using microchannels in which a known-volume portion is loaded at a concentration chosen to allow, for a majority of the time, at most one cell per microchannel at a given time, followed by detecting each cell and either counting or measuring a property at repeated time points. Growth rate is then calculated from changes in count per fluid volume or the measured property between times, while an agent with unknown effect on growth rate is added to the culture(s). Claims also cover scaling from single-culture portions to panels/vials and to multiple microchannels assigned to different cultures.
Stated Advantages
Documented Applications
No documented applications found
Interested in licensing this patent?