Quantitative dielectrophoretic tracking for characterization and separation of persistent subpopulations of Cryptosporidium parvum

摘要: Microbial persistence to antibiotics is attributed subpopulations with phenotypic variations that cause a spread of susceptibility levels, leading the recurrence infections and stability biofilms. Herein, persistent oocyst identified by animal infectivity excystation assays during disinfection Cryptosporidium parvum, water-borne pathogen capable causing enteric at ultra-low doses, are separated characterized quantitative dielectrophoretic tracking over wide frequency range (10 kHz–10 MHz). To enable simultaneous facile individual oocysts, insulator constrictions in microfluidic channel utilized spatially modulate localized field extent needed for defining trajectories obtaining high-resolution displacement versus time measurements under both, positive negative dielectrophoresis. In this manner, obviating need averaging data large collection region, force response more sensitive differences electrophysiology from sub-population fractions. Hence, oocysts after heat silver nanoparticle treatments can be quantified correlating low frequencies (<100 kHz) integrity wall high (0.4–1 MHz) sporozoites oocyst. This label-free method characterize heterogeneous microbial samples phenotypically different alterations, quantifying intensity alteration fraction particular type.