SARS-CoV-2 Isolates from Urine, Placenta, and Nasopharyngeal Samples Reveal No Evidence of Tissue-Specific Mutation Signatures

We conducted a comparative mutation analysis of <b>SARS-CoV-2 sequences isolated from urine, placenta, and nasopharyngeal samples</b>, using Nextclade outputs to identify potential tissue-specific evolutionary patterns. Our findings indicate:<b>No Spike mutations were unique to non-respiratory tissues </b>(urine/placenta), suggesting that these isolates do not reflect adaptation to ACE2-expressing organs.<b>Private mutations were observed across all tissue types </b>, but none were shared across tissues or clustered in specific proteins, indicating general intra-host evolution rather than compartmentalized replication.<b>Mutation profiles were largely uniform </b>across biological matrices, consistent with systemic viremia rather than localized adaptation.These results support the hypothesis that <b>SARS-CoV-2 presence in non-respiratory tissues reflects generalized infection rather than tissue-specific evolution or tropism </b>. This baseline data may inform future studies exploring viral persistence or extrapulmonary shedding.