Viral Shedding in Mice following Intravenous Adenovirus Injection: Impact on Biosafety Classification

Abstract

There have been numerous advances in gene therapy and oncolytic virotherapy in recent years, especially with respect to cutting-edge animal models to test these novel therapeutics. With all of these advances, it is important to understand the biosafety risks of testing these vectors in animals. We performed adenovirus-based viral shedding studies in murine models to ascertain when it is appropriate to downgrade the animals from Biosafety Level (BSL) 2 to BSL 1 for experimental handling and transport. We utilized intravenous injections of a replication-competent adenovirus and analyzed viral shedding via the collection of buccal and dermal swabs from each animal, in addition to obtaining urine and stool samples. The adenovirus hexon copy number was determined by qPCR, and plaque formation was analyzed to assess the biologic activity of viral particles. Our results demonstrate that after 72 h following viral inoculation, there is no significant quantity of biologically active virus shedding from the animals. This observation suggests that on day 4 following adenovirus injection, mice can be safely downgraded to BSL 1 for the remainder of the experiment with no concern for hazardous exposure to laboratory personnel.

Comparison of de novo assembly using long-read shotgun metagenomic sequencing of viruses in fecal and serum samples from marine mammals

“…Future studies could incorporate the use of biotinylated oligonucleotide probes (targeted viral enrichment) to capture viruses from complex matrices after sequencing library preparation to avoid upstream enzymatic treatments ( Briese et al, 2015 ; Martínez-Puchol et al, 2020 , 2022 ; Bonny et al, 2021 ). Although several studies use filtration ( Allen et al, 2011 ; Fontenele et al, 2019 ; Garcia-Heredia et al, 2021 ; Patterson et al, 2021 ; Crum et al, 2023 ; LaRocca et al, 2023 ) to reduce background host and bacterial nucleic acids, it too can cause losses of viruses in filtration.…”