RESUMO
The emerging pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) critically challenges early and accurate virus diagnoses. However, the current gold standard for SARS-CoV-2 detection, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), has reportedly failed to detect low-viral loads. One compound, graphene oxide (GO), which adsorbs single-stranded DNA (ssDNA), has been widely applied in molecular pathogen detection. This study presents a highly sensitive GO-multiplex qPCR method for simultaneous detection of two SARS-CoV-2 genes (RdRP and E) and one reference gene (RNase P). In a GO-multiplex qPCR system, GO pre-absorbs each forward primer to form specific GO-forward primer composites before entering the amplification system. Target gene amplification is confined within the primer-enriched composites, thus, improving the sensitivity of the assay. Compared to conventional multiplex qPCR, GO-multiplex qPCR reduces the limit of detection by 10-fold to 10 copies/reaction. Hence, the GO-multiplex qPCR assay can be effectively used for SARS-CoV-2 detection.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Teste para COVID-19 , Técnicas de Laboratório Clínico/métodos , COVID-19/diagnóstico , RNA Viral/genética , RNA Viral/análise , Sensibilidade e EspecificidadeRESUMO
Staphylococcus aureus is a common pathogen that causes various infections. Therefore, it is crucial to develop a fast and easy detection method for diagnosing and preventing S. aureus infections. In this study, MIRA assay was developed and validated (specificity; 100%) for the detection of S. aureus with nuc as the target gene. The reaction temperature and reaction time were then optimized, and the best reaction was at 40°C, 20 min. The assay could detect S. aureus in only 25 min. Additionally, the limit of detection of MIRA was 5 × 102 CFU/ml, 10-fold lower than that of the traditional PCR. Furthermore, this assay efficiently detected 219 S. aureus of 335 strains obtained from different bacterial samples (detection accuracy; 99.40%). In conclusion, this study provides a rapid and easy-to-operate method for the detection of S. aureus, and thus can be used for the timely diagnosis and prevention of S. aureus infection.
RESUMO
INTRODUCTION: The aetiology of gastric cancer is still unclear but Helicobacter pylori (HP) infection and chronic atrophic gastritis (AG) are recognised as two major risk factors for gastric cancer. GastroPanel (GP) test is the first non-invasive diagnostic tool to detect AG and HP infection.The aim of the study is to conduct a systematic review and meta-analysis to review published literature about the GP test for diagnosing AG and HP infection, with the objective of estimating the diagnostic performance indices of GP for AG and HP infection. METHODS AND ANALYSIS: This protocol of systematic review and meta-analysis is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols statement guidelines. PubMed, Embase, Web of Science and Cochrane Library databases will be systematically searched from inception to March 2022 for eligible studies. No language limitations were imposed. The studies will be downloaded into the EndNote V.X9 software and duplicates will be removed. Two review authors independently screened the full text against the inclusion criteria, extracted the data from each included study by using a piloted data extraction form and conducted risk of bias assessment, resolving disagreement by discussion. Results will be synthesised narratively in summary tables, using a random-effect bivariate model, and we fit a hierarchical summary receiver operating characteristic curve. ETHICS AND DISSEMINATION: This systematic review will include data extracted form published studies, therefore, does not require ethics approval. The results of this study will be submitted to a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42021282616.
