ABSTRACT
Crude polysaccharides, extracted from two seaweed species (Hizikia fusiforme and Sargassum horneri) and Haliotis discus hannai (abalone) viscera, were evaluated for their inhibitory effect against SARS-CoV-2 propagation. Plaque titration revealed that these crude polysaccharides efficiently inhibited SARS-CoV-2 propagation with IC50 values ranging from 0.35 to 4.37 µg/mL. The crude polysaccharide of H. fusiforme showed the strongest antiviral effect, with IC50 of 0.35 µg/mL, followed by S. horneri and abalone viscera with IC50 of 0.56 and 4.37 µg/mL, respectively. In addition, immunofluorescence assay, western blot, and quantitative RT-PCR analysis verified that these polysaccharides could inhibit SARS-CoV-2 replication. In Vero E6 cells, treatment with these crude polysaccharides before or after viral infection strongly inhibited the expression level of SARS-CoV-2 spikes, nucleocapsid proteins, and RNA copies of RNA-dependent RNA-polymerase and nucleocapsid. These results show that these crude marine polysaccharides effectively inhibit SARS-CoV-2 propagation by interference with viral entry.
Subject(s)
COVID-19 Drug Treatment , Seaweed , Antiviral Agents/pharmacology , Humans , Polysaccharides/pharmacology , RNA , SARS-CoV-2 , VisceraABSTRACT
We report pilot studies to evaluate the susceptibility of common domestic livestock (cattle, sheep, goat, alpaca, rabbit, and horse) to intranasal infection with SARS-CoV-2. None of the infected animals shed infectious virus via nasal, oral, or faecal routes, although viral RNA was detected in several animals. Further, neutralizing antibody titres were low or non-existent one month following infection. These results suggest that domestic livestock are unlikely to contribute to SARS-CoV-2 epidemiology.
Subject(s)
COVID-19/veterinary , Host Specificity , Livestock/virology , SARS-CoV-2/pathogenicity , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/virology , Camelids, New World/virology , Cattle/virology , Chlorocebus aethiops , Disease Reservoirs/virology , Goats/virology , Horses/virology , Host Specificity/immunology , Humans , Nasal Cavity/virology , RNA, Viral/analysis , Rabbits/virology , Rectum/virology , Respiratory System/virology , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Sheep/virology , Species Specificity , Vero Cells , Virus Shedding , Viscera/virologyABSTRACT
A high incidence of thrombotic events has been reported in patients with coronavirus disease (COVID-19), which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. We report 3 clinical cases of patients in Italy with COVID-19 who developed abdominal viscera infarction, demonstrated by computed tomography.