Identification and complete genome sequencing of human adenovirus type 55 isolated from a patient with acute hemorrhagic conjunctivitis / 上海预防医学

ObjectiveTo determine the genomic characteristics of a subgenus B human adenovirus strain isolated in Shanghai in 2021. MethodsAn adenovirus type 55 strain was isolated and identified from a patient with acute hemorrhagic conjunctivitis （AHC）. Complete genome of the strain was obtained using the next-generation sequencing （NGS）. Phylogenetic trees were reconstructed based on the sequences of Hexon， Fiber， Penton and complete genome to genomically characterize this strain. ResultsPhylogenetic analysis based on the complete genome classified this strain （MH2021001） into subgenus B， subspecies B2 of HAdV-55. Hexon gene of MH2021001 had close phylogenetic relationship with HAdV-11， while Fiber and Penton genes had close relationship with HAdV-14. The MH2021001 showed high nucleotide identity with currently prevalent HAdV⁃55 strains （>99.90%）. The complete genome had 99.96% nucleotide identity to the 73-GD_CHN_2016 strain isolated in Guangdong. In addition， the amino acid sequence of MH2021001 had several substitutions in regions coding for E1B， L4， E3 and L5. ConclusionThis strain has been classified to HAdV-B55. No recombination event is identified in the complete genome. Due to multiple amino acid substitutions， the biological characteristics of the strain need to be further identified.

Isolation and identification of a severe acute respiratory syndrome coronavirus 2 strain in feces from COVID-19 patients in Shanghai / 上海预防医学

ObjectiveTo isolate and study the biological characteristics of severe acute respiratory syndrome coronavirus 2 （SARS-CoV-2） from feces of coronavirus disease 2019 （COVID-19） patients. MethodsVero E6 cells were used for virus isolation and the isolated strains were tested by nucleic acid test， immunofluorescence test， virulence test and whole genome sequencing. 50% tissue culture infective dose （TCID50） was calculated after the cell cultures of each generation were collected ResultsEight fecal specimens were inoculated with Vero E6 cells after treatment and cultured for 48 h. One specimen showed obvious cytopathic effect on Vero E6 cells. One SARS-CoV-2 out of 8 fecal samples from COVID-19 patients were isolated， and separation rate was 12.5%. The TCID50 of P1， P2 and P3 were 104.0/0.2 mL， 104.5/0.2 mL and 104.75/0.2 mL， respectively. Only one of the 8 stool samples had SARS-CoV-2 virus replication and amplification， and the Ct value of the nucleic acid detection was about 10. The sequence of the isolation was more than 99.99% homologous with that of Wuhan-Hu-1（GenBank MN908947）. ConclusionThe SARS-CoV-2 strain is isolated from the fecal samples of COVID-19 cases and is confirmed by genomic sequencing and immunofluorescence test， which indicates the presence of live virus in feces of COVID-19 cases.