ABSTRACT
COVID-19 is a spectrum of clinical symptoms in humans caused by infection with SARS-CoV-2, a recently emerged coronavirus that has rapidly caused a pandemic. Coalescence of a second wave of this virus with seasonal respiratory viruses, particularly influenza virus is a possible global health concern. To investigate this, transgenic mice expressing the human ACE2 receptor driven by the epithelial cell cytokeratin-18 gene promoter (K18-hACE2) were first infected with IAV followed by SARS-CoV-2. The host response and effect on virus biology was compared to K18-hACE2 mice infected with IAV or SARS-CoV-2 only. Infection of mice with each individual virus resulted in a disease phenotype compared to control mice. Although SARS-CoV-2 RNA synthesis appeared significantly reduced in the sequentially infected mice, these mice had a more rapid weight loss, more severe lung damage and a prolongation of the innate response compared to singly infected or control mice. The sequential infection also exacerbated the extrapulmonary manifestations associated with SARS-CoV-2. This included a more severe encephalitis. Taken together, the data suggest that the concept of twinfection is deleterious and mitigation steps should be instituted as part of a comprehensive public health response to the COVID-19 pandemic.
ABSTRACT
COVID-19 is a complex disease phenotype where the underlying microbiome could influence morbidity and mortality. Amplicon and metagenomic MinION based sequencing was used to rapidly (within 8 hours) identify SARS-CoV-2 and assess the microbiome in nasopharyngeal swabs obtained from patients with COVID-19 by the ISARIC 4C consortium.
ABSTRACT
The objective of this study was to investigate the function of vimentin in PRRSV infection. Vimentin gene from Marc-145 cells was amplified by RT-PCR, cloned into pET-28a vector and expressed in Escherichia coli BL21(DE3). The expressed vimentin was confirmed by Western blot and purified which was used to immunize BALB/c mice for the production of antibodies. Vimentin and antibodies were tested for blocking PRRSV infection of Marc-145 cells. The binding of vimentin to PRRSV N and GP5 proteins were tested by the ELISA. The results showed that vimentin gene was amplified successfully and expressed as identified by SDS-PAGE and Western blot. Mouse anti-vimentin antibodies were produced with the titer of 10(5). PRRSV infection of Marc-145 cells was blocked partially by vimentin while blocked completely by the antibobies. In addition, vimentin was bound N protein, but not GP5. These results provide additional information on PRRSV entry into Marc-145 cells.