Point-of-care testing system for digital single cell detection of MRSA directly from nasal swabs

We present an automated point-of-care testing (POCT) system for rapid detection of species- and resistance markers in methicillin-resistant Staphylococcus aureus (MRSA) at the level of single cells, directly from nasal swab samples. Our novel system allows clear differentiation between MRSA, methicillin-sensitive S. aureus (MSSA) and methicillin-resistant coagulase-negative staphylococci (MR-CoNS), which is not the case for currently used real-time quantitative PCR based systems. On top, the novel approach outcompetes the culture-based methods in terms of its short time-to-result (1 h vs. up to 60 h) and reduces manual labor. The walk-away test is fully automated on the centrifugal microfluidic LabDisk platform. The LabDisk cartridge comprises the unit operations swab-uptake, reagent pre-storage, distribution of the sample into 20 000 droplets, specific enzymatic lysis of Staphylococcus spp. and recombinase polymerase amplification (RPA) of species (vicK) – and resistance (mecA) -markers. LabDisk actuation, incubation and multi-channel fluorescence detection is demonstrated with a clinical isolate and spiked nasal swab samples down to a limit of detection (LOD) of 3 ± 0.3 CFU μl−1 for MRSA. The novel approach of the digital single cell detection is suggested to improve hospital admission screening, timely decision making, and goal-oriented antibiotic therapy. The implementation of a higher degree of multiplexing is required to translate the results into clinical practice. © 2020 The Royal Society of Chemistry.ISSN:1473-0197ISSN:1473-018

DEVELOPMENT OF PROCESS, SIMULATION OF CONCENTRATION PROCESS OF OXIDIZED IRON AND CHROMIUM ORES IN SUSPENSION HYDROCYCLONES

There the hydrocyclone process has been studied as alternative for the jigging in view to decrease of losses of valuable components in concentration of oxidized iron ores. The study of flow pattern by means of air-buble flares of rate transducers and by means of photography allowed to confirm the existence of high-rate (up to 1,2 m/s) local radial flow in the field of edge of outlet. The separation mechanism in two- and three-product (with coaxial tubes) hydrocyclones has been offered. The optimum relations of lengthes of internal branch pipes and of cylindrical part of hydrocyclone have been ascertained. The factors which provide for maximum of separation density have been recommended on the basis of methods of hydromechanics and mechanics. The simulator of hydrocyclone process (as the set of regression equations) and the calculation procedure of loads of regeneration system and of expectable production indicators of concentration have been developed. The effectiveness of developed concentration process has been checked under the industrial conditions. The developed concentration process of chromium ores has been accepted for use in the Don Ore Mining-and-Processing Enterprise. The study results may by used for design, for prediction estimation of concentrating capacity of ores and in the educational processAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio