A comparison of SARS-CoV-2 RNA extraction with the QuickGene-810 Nucleic Acid Isolation System compared to the EZ1 Advanced DSP Virus Kit.

The QuickGene-810 Nucleic Acid Isolation System is a semi-automated extraction platform which may be used for RNA extraction. New methods were required to support the rapid increase in respiratory virus testing during the SARS-CoV-2 pandemic. The aim of this study was to assess SARS-CoV-2 RNA extraction using the QuickGene-810 kit compared to the EZ1 Advanced Extraction Platform for use on the AusDiagnostics SARS-CoV-2, Influenza and RSV 8-well RT-PCR assay. Qualitative results from all clinical samples were concordant between the QuickGene-810 and the EZ1 extraction methods, demonstrating that the QuickGene-810 kit is suitable for use in pathogen diagnostics. However, there was an average difference of approximately two cycles between the cycle threshold (Ct) values for both SARS-CoV-2 targets, suggesting that the EZ1 kit yields a higher concentration of nucleic acid extract, possibly related to its use of carrier RNA and/or smaller elution volume, which infers the possibility of false negative results for samples with very low viral loads.

Efficacy of aerosolized hydrogen peroxide (Deprox) cleaning compared to physical cleaning in a Burns Unit.

BACKGROUND: The performance of Deprox aerosolized hydrogen peroxide (aHP) has not been extensively studied in real-world clinical settings. A comparative study of aHP terminal disinfection was conducted in a Burns Unit and its performance compared to physical cleaning alone. METHODS: Environmental surfaces were sampled pre-cleaning, post-cleaning and post-aHP disinfection. Samples were cultured for MRSA, VRE, Gram-negative multi-resistant organisms and other Gram-negative bacilli. RESULTS: 310 sites were sampled. There was a reduction in the rates of contaminated surfaces post-aHP, though pathogens were still recoverable in most cases, except for VRE. There was a marked reduction in MRSA contamination of soft surfaces (12% post-clean vs 6% post-aHP), and patient room surfaces (8.3% post-clean vs 2.8% post-aHP). It does not work as well for MRSA in bathrooms: 7% of surfaces were positive post-clean, and 9% post-aHP. There was a reduction in multiresistant Gram-negative bacteria (7%-3%), mostly due to drains (33%-13%). CONCLUSION: aHP is a useful method of environmental disinfection, especially for Gram-negative pathogens in drains and MRSA on hard and soft surfaces. Where ongoing acquisition of MRSA is a problem, an adjunctive method of terminal disinfection in bathrooms could be considered.

[Research on the Fluorescence Enhancement Effect of Silver Nanoparticles on the Cholesterol].

Based on traditional fluorescence spectroscopy and metal nanoparticles-enhanced fluorescence technology, this research explores a method of improving the accuracy and resolution of cholesterol detected by fluorescence spectroscopy in human whole blood solution. In experiment, an adult blood with silver nanoparticles is radiated by a laser pulse with wavelength of 407 nm, the fluorescence enhancement effect of cholesterol in blood is studied. The results show that, colloidal silver nanoparticles can enhance the fluorescence intensity of cholesterol in human blood with low concentration significantly. With the increase of the amount of silver colloids, the enhanced efficiency of fluorescence peaks at different positions increases first, and then decreases. However, the strongest enhanced efficiency of fluorescence peaks is different corresponding to different amount of silver colloids. According to the experimental results and the distribution of cholesterol molecules and silver nanoparticles in solution, molecular spatial distribution model is established by theoretical analyses, and the optimal distance for efficient fluorescence enhancement between cholesterol molecules and silver nanoparticles is calculated, the range is 12.19-25 nm, and the result is in good agreement with the theoretical values in other literatures. In summary, the fluorescence intensity of cholesterol in human blood can be enhanced by colloidal silver nanoparticles, and the results also provide a valuable reference on improving the sensitivity and accuracy of cholesterol detection.