TY - JOUR T1 - Real-time respiration changes as a viability indicator for rapid antibiotic susceptibility testing in a microfluidic chamber array JF - bioRxiv DO - 10.1101/2021.01.02.425088 SP - 2021.01.02.425088 AU - Petra Jusková AU - Steven Schmitt AU - André Kling AU - Darius G. Rackus AU - Martin Held AU - Adrian Egli AU - Petra S. Dittrich Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/01/03/2021.01.02.425088.abstract N2 - Rapid identification of a pathogen and the measurement of its antibiotic susceptibility are key elements in the diagnostic process of bacterial infections. Microfluidic technologies offer great control over handling and manipulation of low sample volumes with the possibility to study microbial cultures on the single-cell level. Downscaling the dimensions of cultivation systems directly results in a lower number of bacteria required for antibiotic susceptibility testing (AST) and thus in a reduction of the time to result. The developed platform presented in this work allows the reading of pathogen resistance profiles within 2-3 hours based on the changes of the dissolved oxygen levels during bacterial cultivation. The platform contains hundreds of individual growth chambers prefilled with a hydrogel containing oxygen-sensing nanoprobes and different concentrations of antibiotic compounds. The performance of the microfluidic platform is tested using quality control Escherichia coli strains (ATCC 25922 and ATCC 35218) in response to different clinically relevant antibiotics. The achieved results are in agreement with values given in clinical reference guides and independent measurements using a clinical AST protocol. Finally, the platform is successfully used for AST of an E. coli clinical isolate obtained from a patient blood culture.Competing Interest StatementThe authors have declared no competing interest.ABBREVIATIONSATBantibiotic;ASTantibiotic susceptibility testing;COCcyclic olefin copolymer;MHB IIMueller Hinton Broth II, cation adjusted;MICminimal inhibitory concentration;PDMSpolydimethylsiloxane;PFOTStrichloro (1H,1H,2H,2H-perfluorooctyl) silane ROI, region of interest;sfGFPsuperfolder variant of the green fluorescent protein ER -