	US 12,203,124 B2
	Methods for improved rapid antimicrobial susceptibility testing
Eric Stern, Charlestown, MA (US); Aleksandar Vacic, Charlestown, MA (US); Kelly Flentie, Charlestown, MA (US); Benjamin Spears, Charlestown, MA (US); and Felicia Chen, Charlestown, MA (US)
Assigned to SELUX DIAGNOSTICS, INC., Charlestown, MA (US)
Appl. No. 16/472,714
Filed by SELUX DIAGNOSTICS, INC., Charlestown, MA (US)
PCT Filed Dec. 22, 2017, PCT No. PCT/US2017/068306 § 371(c)(1), (2) Date Jun. 21, 2019, PCT Pub. No. WO2018/119439, PCT Pub. Date Jun. 28, 2018.
Claims priority of provisional application 62/535,106, filed on Jul. 20, 2017.
Claims priority of provisional application 62/488,454, filed on Apr. 21, 2017.
Claims priority of provisional application 62/438,780, filed on Dec. 23, 2016.
Prior Publication US 2020/0149086 A1, May 14, 2020
Int. Cl. C12Q 1/18 (2006.01); C07D 257/04 (2006.01); C07D 403/10 (2006.01); C07D 417/04 (2006.01); C07F 5/00 (2006.01); G01N 21/64 (2006.01)

CPC C12Q 1/18 (2013.01) [C07D 257/04 (2013.01); C07D 403/10 (2013.01); C07D 417/04 (2013.01); C07F 5/003 (2013.01); G01N 21/6408 (2013.01)]

14 Claims

1. A method for determining antimicrobial susceptibility of a microorganism comprising:

introducing suspensions of one or more microorganisms in a medium to at least a first subset of chambers and a second subset of chambers disposed within a cartridge;

incubating the cartridge under conditions promoting microorganism growth for an initial incubation period;

adding one or more antimicrobial agents to the second subset of chambers;

performing one or more checkpoint assays on the first subset of chambers and a third subset of chambers disposed within the cartridge after the initial incubation period to determine if a measured threshold value indicating microorganism growth has been reached or surpassed by a predetermined threshold value, wherein at least one checkpoint assay comprises a growth indicator, further wherein the measured threshold value is a ratio of a positive control in the first subset of chambers, the first subset of chambers comprising the suspension of microorganisms in the medium and the growth indicator without an antimicrobial to a background control in the third subset of chambers, the third subset of chambers comprising the medium and the growth indicator without the microorganisms; and

(a) if the measured threshold value has reached or surpassed the predetermined threshold value after performing the one or more checkpoint assays:

(i) performing one or more growth assays in the second subset of cartridge chambers to determine the microorganism's susceptibility to the one or more antimicrobials; and

(ii) obtaining a minimum inhibitory concentration (MIC) and/or a qualitative susceptibility result (QSR) for the second subset of cartridge chambers; or

(b) if the measured threshold value has not reached or surpassed the predetermined threshold value after performing the one or more checkpoint assays, performing one or more additional incubation periods under conditions promoting microorganism growth until

(i) the measured threshold value has reached or surpassed the predetermined threshold value, and thereafter performing step (a); or

(ii) a maximum of 18 hours has transpired without the predetermined threshold value being reached or surpassed by the measured threshold value and no further assays are performed, wherein at least one of the growth assays comprises performing a surface-binding probe assay by introducing a surface-binding probe comprising a coordination complex of a lanthanide with diethylenetriaminetetraacetic acid or a cryptate ligand and wherein the coordination complex of the lanthanide with diethylenetriaminetetraacetic acid or the cryptate ligand are used for time-resolved fluorescence (TRF) or time-gated luminescence (TGL).