RESUMO
Coronavirus disease 2019 (COVID-19) has become pandemic since March 11, 2020. Thus, development and integration in clinics of fast and sensitive diagnostic tools are essential. The aim of the study is a development and evaluation of a one-step quantitative reverse transcription-polymerase chain reaction (RT-qPCR) assay (COVID-19 Amp) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection with an armored positive control and internal controls constructed from synthetic MS2-phage-based RNA particles. The COVID-19 Amp assay limit of detection was 103 copies/ml, the analytical specificity was 100%. A total of 109 biological samples were examined using COVID-19 Amp and World Health Organization (WHO)-based assay. Discordance in nine samples was observed (negative by the WHO-based assay) and discordant samples were retested as positive according to the results obtained from the Vector-PCRrv-2019-nCoV-RG assay. The developed COVID-19 Amp assay has high sensitivity and specificity, includes virus particles-based controls, provides the direct definition of the SARS-CoV-2 RdRp gene partial sequence, and is suitable for any hospital and laboratory equipped for RT-qPCR.
Assuntos
Teste para COVID-19/métodos , COVID-19/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , SARS-CoV-2/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Testes Diagnósticos de Rotina , Feminino , Genoma Viral/genética , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética , SARS-CoV-2/isolamento & purificação , Sensibilidade e Especificidade , Adulto JovemRESUMO
The development of stimuli-responsive nanocontainers is an issue of utmost importance for many applications such as targeted drug delivery, regulation of the cell and tissue behavior, making bacteria have useful functions and here converting light. The present work shows a new contribution to the design of polyelectrolyte (PE) containers based on surface modified mesoporous titania particles with deposited Ag nanoparticles to achieve chemical light upconversion via biofilms. The PE shell allows slowing down the kinetics of a release of loaded l-arabinose and switching the bacteria luminescence in a certain time. The hybrid TiO2/Ag/PE containers activated at 980 nm (IR) illumination demonstrate 10 times faster release of l-arabinose as opposed to non-activated containers. Fast IR-released l-arabinose switch bacteria fluorescence which we monitor at 510 nm. The approach described herein can be used in many applications where the target and delayed switching and light upconversion are required.
