Isolation of a SARS-CoV-2 strain from pediatric patients in South Korea:
Biologic and genetic characterization
Abstract
A SARS-CoV-2, N15 strain was successfully isolated from the nasal swab
of a pediatric patient after five blind passages in Vero cells. The
biological properties of this isolate were investigated extensively.
Cytopathic effects (CPE) were observed within 48 hours post- infection,
characterized by aggregates of dead cells. The N15 isolate demonstrated
the ability to replicate across various human-origin cell lines, albeit
with different growth kinetics. Genetic analyses revealed that the
strain belongs to the 19B lineage of SARS-CoV-2, showing 99.9%
similarity to the original Wuhan 1 strain. Importantly, the N15 strain
did not exhibit genetic signatures of in-vitro adaptation and
possessed rare mutations N709S in the spike protein and T11M in the E
protein. Drug testing indicated that Remdesivir, Molnupiravir, and
Nirmatrelvir effectively inhibited this isolate at varying
concentrations. The N15 isolate may serve as valuable material for
comparative studies with currently circulating SARS-CoV-2 variants.