Biology subjects

Kehn-Hall, K.

Publications and source records attributed to Kehn-Hall, K..

4 recordsLinked to original sources

bioRxiv2020

A continuously self-sterilizing form of copper capable of 99% SARS-CoV-2 deactivation in 30 seconds.

The coronavirus disease 2019 (COVID-19) has created an acute worldwide demand for sustained broadband pathogen suppression in households, hospitals, and public spaces. The US recently passed a new sad milestone of 500,000 deaths due to COVID-19, the highest rate anywhere in the world. In response, we have created a rapid-acting, self-sterilizing PPE configurations capable of killing SARS-CoV-2 and other microbes in seconds. The highly active material destroys pathogens faster than any conventional copper configuration. The material maintains its antimicrobial efficacy over sustained use and is shelf stable. We have performed rigorous testing in accordance with guidelines from U.S. governing authorities and believe that the material could offer broad spectrum, non-selective defense against most microbes via integration into masks and other protective equipment. SummaryA novel configuration of copper offering continued fast-acting protection against viruses and bacteria, including SARS-CoV-2.

immunology↗

bioRxiv2020

Silicon Nitride Inactivates SARS-CoV-2 in vitro

IntroductionSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, remains viable and therefore potentially infectious on several materials. One strategy to discourage the fomite-mediated spread of COVID-19 is the development of materials whose surface chemistry can spontaneously inactivate SARS-CoV-2. Silicon nitride (Si3N4), a material used in spine fusion surgery, is one such candidate because it has been shown to inactivate several bacterial species and viral strains. This study hypothesized that contact with Si3N4 would inactivate SARS-CoV-2, while mammalian cells would remain unaffected. MaterialsSARS-CoV-2 virions (2x104 PFU/mL diluted in growth media) were exposed to 5, 10, 15, and 20% (w/v) of an aqueous suspension of sintered Si3N4 particles for durations of 1, 5, and 10 minutes, respectively. Before exposure to the virus, cytotoxicity testing of Si3N4 alone was assessed in Vero cells at 24 and 48 hour post-exposure times. Following each exposure to Si3N4, the remaining infectious virus was quantitated by plaque assay. ResultsVero cell viability increased at 5% and 10% (w/v) concentrations of Si3N4 at exposure times up to 10 minutes, and there was only minimal impact on cell health and viability up to 20% (w/v). However, the SARS-CoV-2 titers were markedly reduced when exposed to all concentrations of Si3N4; the reduction in viral titers was between 85% - 99.6%, depending on the dose and duration of exposure. ConclusionsSi3N4 was non-toxic to the Vero cells while showing strong antiviral activity against SARS-CoV-2. The viricidal effect increased with increasing concentrations of Si3N4 and longer duration of exposure. Surface treatment strategies based on Si3N4 may offer novel methods to discourage SARS-CoV-2 persistence and infectivity on surfaces and discourage the spread of COVID-19.

microbiology↗

bioRxiv2020

Nanotrap(R) particles improve detection of SARS-CoV-2 for pooled sample methods, extraction-free saliva methods, and extraction-free medium methods

Here we present a rapid and versatile method for capturing and concentrating SARS-CoV-2 from transport medium and saliva using affinity-capture magnetic hydrogel particles. We demonstrate that the method concentrates virus prior to RNA extraction, thus significantly improving detection of the virus using a real-time RT-PCR assay across a range of viral titers, from 100 to 1,000,000 viral copies/mL; in particular, detection of virus in low viral load samples is enhanced when using the method coupled with the IDT 2019-nCoV CDC EUA Kit. This method is compatible with commercially available nucleic acid extraction kits, as well with a simple heat and detergent method. Using transport medium diagnostic remnant samples that previously had been tested for SARS-CoV-2 using either the Abbott RealTime SARS-CoV-2 EUA Test (n=14) or the Cepheid Xpert Xpress SARS-CoV-2 EUA Test (n=35), we demonstrate that our method not only correctly identifies all positive samples (n = 17) but also significantly improves detection of the virus in low viral load samples. The average improvement in cycle threshold (Ct) value as measured with the IDT 2019-nCoV CDC EUA Kit was 3.1; n = 10. Finally, to demonstrate that the method could potentially be used to enable pooled testing, we spiked infectious virus or a confirmed positive diagnostic remnant sample into 5 mL and 10 mL of negative transport medium and observed significant improvement in the detection of the virus from those larger sample volumes.

microbiology↗

bioRxiv2020

PSGL-1 blocks SARS-CoV-2 S protein-mediated virus attachment and infection of target cells

P-selectin glycoprotein ligand-1 (PSGL-1) is a cell surface glycoprotein that binds to P-, E-, and L-selectins to mediate the tethering and rolling of immune cells on the surface of the endothelium for cell migration into inflamed tissues. PSGL-1 has been identified as an interferon-γ (INF-γ)-regulated factor that restricts HIV-1 infectivity, and has recently been found to possess broad-spectrum antiviral activities. Here we report that the expression of PSGL-1 in virus-producing cells impairs the incorporation of SARS-CoV and SARS-CoV-2 spike (S) glycoproteins into pseudovirions and blocks virus attachment and infection of target cells. These findings suggest that PSGL-1 may potentially inhibit coronavirus replication in PSGL-1+ cells.Competing Interest StatementThe authors have declared no competing interest.View Full Text

microbiology↗