The global spread of SARS-CoV-2 has made millions ill with COVID-19 and even more from the economic fallout of this pandemic. Our quest to test new therapeutics and vaccines require small animal models that replicate disease phenotypes seen in COVID-19 cases. Rodent models of SARS-CoV-2 infection thus far have shown mild to moderate pulmonary disease; mortality, if any, has been associated with prominent signs of central nervous system (CNS) infection and dysfunction. Here we describe the isolation of SARS-CoV-2 variants with propensity for either pulmonary or CNS infection. Using a wild-type SARS-CoV-2 isolated from a COVID-19 patient, we first found that infection was lethal in transgenic mice expressing the human angiotensin I-converting enzyme 2 (hACE2). Fortuitously, full genome sequencing of SARS-CoV-2 from the brain and lung of these animals showed genetic differences. Likewise, SARS-CoV-2 isolates from brains and lungs of these also showed differences in plaque morphology. Inoculation of these brain and lung SARS-CoV-2 isolates into new batch of hACE2 mice intra-nasally resulted in lethal CNS and pulmonary infection, respectively. Collectively, our study suggests that genetic variants of SARS-CoV-2 could be used to replicate specific features of COVID-19 for the testing of potential vaccines or therapeutics.

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The Duke-NUS Medical School's animal biosafety level 3 facility is fitted with 3 types of equipment for waste decontamination: autoclaves, a tissue digester, and an effluent decontamination system (EDS). Validation of the effectiveness of the decontamination systems and process was done through simulated loads of waste. Biological indicators (BIs) were used to test the efficacy of the decontamination process. Geobacillus stearothermophilus log 10 6 was used for autoclaves and the tissue digester, while Bacillus subtilis and bacteriophages were used for validating the EDS. The loads tested in the autoclave included laundry, solid waste, and animal cages, with BIs placed in locations that were a challenge for steam penetration. The tissue digester was validated with frozen chickens from the supermarket, with BIs placed in the abdominal cavity of the carcass. The optimal weight of sodium hydroxide was that which achieved no growth in the BIs and, on visual inspection, no flesh or marrow on the bony remnants. Liquid waste from the shower, sinks, and downdraft table was routed to the EDS, which was validated with B subtilis and bacteriophage. Bleach was used for decontamination at a concentration >700 ppm of total chlorine. In high-containment facilities, factory and onsite testing and commissioning of waste management systems need to be supplemented by adequate validation processes to ensure the effectiveness of decontamination for the types and amount of waste generated in the facility. This is critical to ensure that no material leaves the facility until it is properly decontaminated.

Introduction: An infectious disease outbreak like the current COVID-19 pandemic can lead to particularly high infection rates in areas where diagnostic laboratory support is limited. The deployment of mobile laboratories can help to detect pathogens, monitor the presence in a population, and inform public health authorities to take measures aimed at reducing pathogen spread. Materials and Methods: Available layouts and operational descriptions of mobile laboratories were analyzed for their suitability for the envisioned purpose and to assure high standards of biosafety and biosecurity. Recent media coverage on creative solutions for the diagnostics of SARS-CoV-2 (drive-through test centers, self-swab, inverse gloveboxes to protect health care workers) from various countries were considered. Results: A minimalistic and optimized design to construct a multifunctional laboratory on the chassis of a regular-sized box truck is proposed and can serve as a blueprint to rapidly develop additional diagnostic capacities. Discussion: For acute health threats including the current COVID-19 outbreak, rapid diagnosis of infection is key to recommend measures aimed at preventing the spread of the pathogen. Laboratory layouts that are similar to the one proposed here are used in stationary setups, and mobile laboratories have been built on varying platforms (trailers, shipping containers, etc).